[enhancement] Version catalogs and questions

[jmfrenzel]

Descriptive summary

Make version functionality available to catalogs and questions.

Affects

Users, Managers, Admins  

Rationale

Context and content of question texts will change regularly, e.g. regulations and laws such as GDPR. However, 

RDMO projects (and it versions) must conserve that particular context and content of the question text at that point in time at which the user was  entering an answer. This will support preservation of RDMO projects. 

Expected behavior

Projects provide the question texts which were present during the answering process including snapshots. 

Optional: Persistent IDs and tags for catalogs

Related work

Link to related tickets or prior related work here.

[jochenklar]

This is actually the same as #333. Both are not about typical versioning (e.g. mediawiki), but about storing the catalog and other content together with the catalog to preserve the context the questions were answered.