handle visibility (public/private) changes
side-effect : any configuration change recreates everything in the datasets-server.
Possibly, the Hub will implement "scope": "repo.config.visibility", but for now, it's the way to react to visibility changes.

fixes #2379 
handle visibility (public/private) changes: side-effect : any configuration change recreates everything in the datasets-server.
Possibly, the Hub will implement "scope": "repo.config.visibility", but for now, it's the way to react to visibility changes.

fixes #2379 