Translation/Synchronization: Support for Folder-Links in Dependent Content

Prior to this fix, documents linking to folders (sometimes used in Settings-documents, for example), could not translated/synchronized from within CoreMedia Studio. A false-positive warning on missing document properties was raised.

With this fix, folders are supported in translation and synchronization workflows as dependent content only . Thus, you may safely translate/synchronize contents linking to folders.

Note, that these folders will not be listed within the workflow's detail view, as folders are considered implicitly created during a translation/synchronization workflow within that view.

(CMS-20636)