Add ability to have a reference picker for the include macro without needing a Group being displayed in the UI and without showing the complex type property in the UI too

Right now it seems that the condition to have the reference picker working is to have both @PropertyGroup("stringReference") and to not have @PropertyHidden set on the type property.

What we need:

• Be able to have a reference picked user for the reference
• Not have a group bow drawn in the WYSIWYG macro editor
• Be able to not display the "type" property which is complex and confusing property that should only be usable by wiki editor users.