Adds graphql type mapping of multiroot treelist as a multilist

GWDT.GraphQL.FieldTypes.patch.config

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/" xmlns:role="http://www.sitecore.net/xmlconfig/role/">
  <sitecore>
    <api>
      <GraphQL>
        <defaults>
          <content>
            <fieldTypeMappings>
              <standardTypeMapping type="Sitecore.Services.GraphQL.Content.TemplateGeneration.FieldTypeToGraphQLTypeMapper, Sitecore.Services.GraphQL.Content">
                <typeMapping hint="raw:AddTypeMapping">
                  <map field="multiroot treelist" type="Sitecore.Services.GraphQL.Content.TemplateGeneration.FieldMapping.MultilistFieldTypeFactory, Sitecore.Services.GraphQL.Content" />
                </typeMapping>
              </standardTypeMapping>
            </fieldTypeMappings>
          </content>
        </defaults>
      </GraphQL>
    </api>
  </sitecore>
</configuration>