Enable HTML code editing in Mosaic tiles

registry.xml

<?xml version="1.0"?>
<registry>
  <records interface="plone.app.mosaic.interfaces.IFormat"
	   prefix="plone.app.mosaic.richtext_toolbar.code">
    <value key="name">toolbar-code</value>
    <value key="category">actions</value>
    <value key="label">Edit Code</value>
    <value key="action">code</value>
    <value key="icon">false</value>
    <value key="favorite">false</value>
    <value key="weight">1000</value>
  </records>
  <record field="actions" interface="plone.app.mosaic.interfaces.IWidgetAction"
	  name="plone.app.mosaic.widget_actions.plone_app_z3cform_wysiwyg_widget_WysiwygWidget.actions">
    <value purge="False">
      <element>toolbar-code</element>
    </value>
  </record>
  <record field="actions" interface="plone.app.mosaic.interfaces.IWidgetAction"
	  name="plone.app.mosaic.widget_actions.plone_app_z3cform_wysiwyg_widget_WysiwygFieldWidget.actions">
    <value purge="False">
      <element>toolbar-code</element>
    </value>
  </record>
  <record field="actions" interface="plone.app.mosaic.interfaces.IWidgetAction"
	  name="plone.app.mosaic.widget_actions.plone_app_widgets_dx_RichTextWidget.actions">
    <value purge="False">
      <element>toolbar-code</element>
    </value>
  </record>
  <record field="actions" interface="plone.app.mosaic.interfaces.IWidgetAction"
	  name="plone.app.mosaic.widget_actions.plone_app_z3cform_widget_RichTextFieldWidget.actions">
    <value purge="False">
      <element>toolbar-code</element>
    </value>
  </record>
  <record name="plone.app.mosaic.structure_tiles.text.available_actions">
    <value purge="False">
      <element>toolbar-code</element>
    </value>
  </record>
  <record name="plone.app.mosaic.app_tiles.plone_app_standardtiles_rawhtml.available_actions">
    <value purge="False">
      <element>toolbar-code</element>
    </value>
  </record>
</registry>