Custom collection must not be a collection member

1. In Configuration / Content Model / Document Types create a document Type
2. Add the Document is a collection facet
3. Observe Document cannot be added to a collection remains unticked

Impact: this circumvents the protection that prevents having collections in collections.
The Collection document type is defined here
it also has the NotCollectionMember facet which is enforced by the collection manager here
This is to avoid scenarios with a collection that contains a collection that contains the previous collection. This could potentially lead to infinite loop in some processes.

Expected behavior: when the Document is a collection facet is ticked and Document cannot be added to a collection facet is not a validation error should be shown.

AC

• When I create a doctype that extends Collection, Document is a collection and Document cannot be added to a collection are activated
• When I activate the Document is a collection facet on a doctype that extends something else, Document cannot be added to a collection facet is activated
• A validation error is displayed in the left tree when a document has facet Document is a collection without Document cannot be added to a collection + message is shown in the feature itself:

  [Document cannot be added to a collection] facet is required when adding the [Document is a collection] one to prevent infinite loops. It will be added automatically next time you save this document type.