Prevent document version addition/change based on access level (stop our requesters from adding versions)

[#1]

Whether accidentally or on purpose, sometimes our requesters add documents as versions of creative drafts added by the designer. Perhaps they accidentally drag-and-drop a new document on top of a document instance in Workfront.

This creates a lot of confusion and extra work for the designer and also messes up the versioning in Workfront.

Prevent users of a certain access level from being able to add a version to document instances that they don't own.