draw icons in the unity hierarchy view (put in your Editor folder)

HierarchyIcons.cs

using UnityEditor;
using UnityEngine;
using System.Collections.Generic;
using UnityEngine.Tilemaps;
using UnityEngine.Timeline;
using UnityEngine.UI;
using UnityEngine.U2D;
using UnityEngine.Rendering;
using UnityEngine.Playables;
using UnityEngine.EventSystems;
using UnityEngine.Video;
using UnityEngine.Experimental.VFX;
using UnityEditor.Animations;
using UnityEngine.Animations;

[InitializeOnLoad]
class HierarchyIcons
{
    private static Dictionary<System.Type, string> m_iconPaths = new Dictionary<System.Type, string>()
    {
    {typeof(GridBrush), "GridBrush Icon"},
    {typeof(Microphone), "Microphone Icon"},
    {typeof(AnimatorController), "AnimatorController Icon"},
    {typeof(AnimatorState), "AnimatorState Icon"},
    {typeof(AnimatorStateMachine), "AnimatorStateMachine Icon"},
    {typeof(AnimatorStateTransition), "AnimatorStateTransition Icon"},
    {typeof(BlendTree), "BlendTree Icon"},
    {typeof(DefaultAsset), "DefaultAsset Icon"},
    {typeof(EditorSettings), "EditorSettings Icon"},
    {typeof(HumanTemplate), "HumanTemplate Icon"},
    {typeof(LightingDataAsset), "LightingDataAsset Icon"},
    {typeof(LightmapParameters), "LightmapParameters Icon"},
    {typeof(SceneAsset), "SceneAsset Icon"},
    {typeof(Animation), "Animation Icon"},
    {typeof(AnimationClip), "AnimationClip Icon"},
    {typeof(AimConstraint), "AimConstraint Icon"},
    {typeof(LookAtConstraint), "LookAtConstraint Icon"},
    {typeof(ParentConstraint), "ParentConstraint Icon"},
    {typeof(PositionConstraint), "PositionConstraint Icon"},
    {typeof(RotationConstraint), "RotationConstraint Icon"},
    {typeof(ScaleConstraint), "ScaleConstraint Icon"},
    {typeof(Animator), "Animator Icon"},
    {typeof(AnimatorOverrideController), "AnimatorOverrideController Icon"},
    {typeof(AreaEffector2D), "AreaEffector2D Icon"},
    {typeof(AudioChorusFilter), "AudioChorusFilter Icon"},
    {typeof(AudioClip), "AudioClip Icon"},
    {typeof(AudioDistortionFilter), "AudioDistortionFilter Icon"},
    {typeof(AudioEchoFilter), "AudioEchoFilter Icon"},
    {typeof(AudioHighPassFilter), "AudioHighPassFilter Icon"},
    {typeof(AudioListener), "AudioListener Icon"},
    {typeof(AudioLowPassFilter), "AudioLowPassFilter Icon"},
    {typeof(AudioReverbFilter), "AudioReverbFilter Icon"},
    {typeof(AudioReverbZone), "AudioReverbZone Icon"},
    {typeof(AudioSource), "AudioSource Icon"},
    {typeof(Avatar), "Avatar Icon"},
    {typeof(AvatarMask), "AvatarMask Icon"},
    {typeof(BillboardAsset), "BillboardAsset Icon"},
    {typeof(BillboardRenderer), "BillboardRenderer Icon"},
    {typeof(BoxCollider), "BoxCollider Icon"},
    {typeof(BoxCollider2D), "BoxCollider2D Icon"},
    {typeof(BuoyancyEffector2D), "BuoyancyEffector2D Icon"},
    {typeof(Camera), "Camera Icon"},
    {typeof(Canvas), "Canvas Icon"},
    {typeof(CanvasGroup), "CanvasGroup Icon"},
    {typeof(CanvasRenderer), "CanvasRenderer Icon"},
    {typeof(CapsuleCollider), "CapsuleCollider Icon"},
    {typeof(CapsuleCollider2D), "CapsuleCollider2D Icon"},
    {typeof(CharacterController), "CharacterController Icon"},
    {typeof(CharacterJoint), "CharacterJoint Icon"},
    {typeof(CircleCollider2D), "CircleCollider2D Icon"},
    {typeof(Cloth), "Cloth Icon"},
    {typeof(CompositeCollider2D), "CompositeCollider2D Icon"},
    {typeof(ComputeShader), "ComputeShader Icon"},
    {typeof(ConfigurableJoint), "ConfigurableJoint Icon"},
    {typeof(ConstantForce), "ConstantForce Icon"},
    {typeof(ConstantForce2D), "ConstantForce2D Icon"},
    {typeof(Cubemap), "Cubemap Icon"},
    {typeof(DistanceJoint2D), "DistanceJoint2D Icon"},
    {typeof(EdgeCollider2D), "EdgeCollider2D Icon"},
    {typeof(EventSystem), "EventSystem Icon"},
    {typeof(EventTrigger), "EventTrigger Icon"},
    {typeof(Physics2DRaycaster), "Physics2DRaycaster Icon"},
    {typeof(PhysicsRaycaster), "PhysicsRaycaster Icon"},
    {typeof(StandaloneInputModule), "StandaloneInputModule Icon"},
    {typeof(VisualEffect), "VisualEffect Icon"},
    {typeof(VisualEffectAsset), "VisualEffectAsset Icon"},
    {typeof(FixedJoint), "FixedJoint Icon"},
    {typeof(FixedJoint2D), "FixedJoint2D Icon"},
    {typeof(Flare), "Flare Icon"},
    {typeof(FlareLayer), "FlareLayer Icon"},
    {typeof(Font), "Font Icon"},
    {typeof(FrictionJoint2D), "FrictionJoint2D Icon"},
    {typeof(GameObject), "GameObject Icon"},
    {typeof(Grid), "Grid Icon"},
    {typeof(GUISkin), "GUISkin Icon"},
    {typeof(HingeJoint), "HingeJoint Icon"},
    {typeof(HingeJoint2D), "HingeJoint2D Icon"},
    {typeof(LensFlare), "LensFlare Icon"},
    {typeof(Light), "Light Icon"},
    {typeof(LightProbeGroup), "LightProbeGroup Icon"},
    {typeof(LightProbeProxyVolume), "LightProbeProxyVolume Icon"},
    {typeof(LightProbes), "LightProbes Icon"},
    {typeof(LineRenderer), "LineRenderer Icon"},
    {typeof(LODGroup), "LODGroup Icon"},
    {typeof(Material), "Material Icon"},
    {typeof(Mesh), "Mesh Icon"},
    {typeof(MeshCollider), "MeshCollider Icon"},
    {typeof(MeshFilter), "MeshFilter Icon"},
    {typeof(MeshRenderer), "MeshRenderer Icon"},
    {typeof(Motion), "Motion Icon"},
    {typeof(OcclusionArea), "OcclusionArea Icon"},
    {typeof(OcclusionPortal), "OcclusionPortal Icon"},
    {typeof(ParticleSystem), "ParticleSystem Icon"},
    {typeof(ParticleSystemForceField), "ParticleSystemForceField Icon"},
    {typeof(PhysicMaterial), "PhysicMaterial Icon"},
    {typeof(PhysicsMaterial2D), "PhysicsMaterial2D Icon"},
    {typeof(PlatformEffector2D), "PlatformEffector2D Icon"},
    {typeof(PlayableDirector), "PlayableDirector Icon"},
    {typeof(PointEffector2D), "PointEffector2D Icon"},
    {typeof(PolygonCollider2D), "PolygonCollider2D Icon"},
    {typeof(Projector), "Projector Icon"},
    {typeof(RectTransform), "RectTransform Icon"},
    {typeof(ReflectionProbe), "ReflectionProbe Icon"},
    {typeof(RelativeJoint2D), "RelativeJoint2D Icon"},
    {typeof(SortingGroup), "SortingGroup Icon"},
    {typeof(RenderTexture), "RenderTexture Icon"},
    {typeof(Rigidbody), "Rigidbody Icon"},
    {typeof(Rigidbody2D), "Rigidbody2D Icon"},
    {typeof(ScriptableObject), "ScriptableObject Icon"},
    {typeof(Shader), "Shader Icon"},
    {typeof(ShaderVariantCollection), "ShaderVariantCollection Icon"},
    {typeof(SkinnedMeshRenderer), "SkinnedMeshRenderer Icon"},
    {typeof(Skybox), "Skybox Icon"},
    {typeof(SliderJoint2D), "SliderJoint2D Icon"},
    {typeof(SphereCollider), "SphereCollider Icon"},
    {typeof(SpringJoint), "SpringJoint Icon"},
    {typeof(SpringJoint2D), "SpringJoint2D Icon"},
    {typeof(Sprite), "Sprite Icon"},
    {typeof(SpriteMask), "SpriteMask Icon"},
    {typeof(SpriteRenderer), "SpriteRenderer Icon"},
    {typeof(StreamingController), "StreamingController Icon"},
    {typeof(SurfaceEffector2D), "SurfaceEffector2D Icon"},
    {typeof(TargetJoint2D), "TargetJoint2D Icon"},
    {typeof(Terrain), "Terrain Icon"},
    {typeof(TerrainCollider), "TerrainCollider Icon"},
    {typeof(TerrainData), "TerrainData Icon"},
    {typeof(TextAsset), "TextAsset Icon"},
    {typeof(TextMesh), "TextMesh Icon"},
    {typeof(Texture), "Texture Icon"},
    {typeof(Texture2D), "Texture2D Icon"},
    {typeof(Tile), "Tile Icon"},
    {typeof(Tilemap), "Tilemap Icon"},
    {typeof(TilemapCollider2D), "TilemapCollider2D Icon"},
    {typeof(TilemapRenderer), "TilemapRenderer Icon"},
    {typeof(TimelineAsset), "TimelineAsset Icon"},
    {typeof(TrailRenderer), "TrailRenderer Icon"},
   // {typeof(Transform), "Transform Icon"},
    {typeof(SpriteAtlas), "SpriteAtlas Icon"},
    {typeof(AspectRatioFitter), "AspectRatioFitter Icon"},
    {typeof(Button), "Button Icon"},
    {typeof(CanvasScaler), "CanvasScaler Icon"},
    {typeof(ContentSizeFitter), "ContentSizeFitter Icon"},
    {typeof(Dropdown), "Dropdown Icon"},
    {typeof(GraphicRaycaster), "GraphicRaycaster Icon"},
    {typeof(GridLayoutGroup), "GridLayoutGroup Icon"},
    {typeof(HorizontalLayoutGroup), "HorizontalLayoutGroup Icon"},
    {typeof(Image), "Image Icon"},
    {typeof(InputField), "InputField Icon"},
    {typeof(LayoutElement), "LayoutElement Icon"},
    {typeof(Mask), "Mask Icon"},
    {typeof(Outline), "Outline Icon"},
    {typeof(PositionAsUV1), "PositionAsUV1 Icon"},
    {typeof(RawImage), "RawImage Icon"},
    {typeof(RectMask2D), "RectMask2D Icon"},
    {typeof(Scrollbar), "Scrollbar Icon"},
    {typeof(ScrollRect), "ScrollRect Icon"},
    {typeof(Selectable), "Selectable Icon"},
    {typeof(Shadow), "Shadow Icon"},
    {typeof(Slider), "Slider Icon"},
    {typeof(Text), "Text Icon"},
    {typeof(Toggle), "Toggle Icon"},
    {typeof(ToggleGroup), "ToggleGroup Icon"},
    {typeof(VerticalLayoutGroup), "VerticalLayoutGroup Icon"},
    {typeof(VideoClip), "VideoClip Icon"},
    {typeof(VideoPlayer), "VideoPlayer Icon"},
    {typeof(WheelCollider), "WheelCollider Icon"},
    {typeof(WheelJoint2D), "WheelJoint2D Icon"},
    {typeof(WindZone), "WindZone Icon"},
    {typeof(MonoBehaviour), "cs Script Icon"},
    };

    private static Dictionary<System.Type, GUIContent> m_icons = new Dictionary<System.Type, GUIContent>();

    private static Dictionary<int, Dictionary<System.Type, int>> m_objectMap = new Dictionary<int, Dictionary<System.Type, int>>();

    static HierarchyIcons()
    {
        foreach ( var kvp in m_iconPaths)
        {
            m_icons[kvp.Key] = EditorGUIUtility.IconContent(kvp.Value);
        }

        EditorApplication.hierarchyWindowItemOnGUI += HierarchyItemCB;
        EditorApplication.hierarchyChanged += UpdateList;
        UpdateList();
    }

    static void UpdateList()
    {
        GameObject[] go = Object.FindObjectsOfType(typeof(GameObject)) as GameObject[];

        foreach (GameObject g in go)
        {
            var id = g.GetInstanceID();
            var components = g.GetComponents<Component>();
            var typeList = new List<System.Type>();

            m_objectMap[id] = new Dictionary<System.Type, int>();

            foreach (Component c in components)
            {
                var type = c.GetType();

                if ( type.IsSubclassOf(typeof(MonoBehaviour)))
                {
                    type = typeof(MonoBehaviour);
                }

                if (!m_objectMap[id].ContainsKey(type))
                {
                    m_objectMap[id][type] = 1;
                }
                else
                {
                    m_objectMap[id][type]++;
                }
            }
        }
    }

    static void HierarchyItemCB(int instanceID, Rect selectionRect)
    {
        if (m_objectMap.ContainsKey(instanceID))
        {
            Rect r = new Rect(selectionRect);

            r.x = r.width;
            r.width = 18;

            foreach (var typeAndCount in m_objectMap[instanceID])
            {
                if (m_icons.ContainsKey(typeAndCount.Key))
                {
                    r.x -= 15;
                    GUI.Label(r, m_icons[typeAndCount.Key]);
                    if (typeAndCount.Value > 1)
                    {
                        GUI.Label(r, typeAndCount.Value.ToString());
                    }

                }
            }
        }
    }
}