V16: Cache Version Mechanism

[nikolajlauridsen]

This pull request introduces a new cache versioning mechanism for repositories, helping to ensure cache consistency with the database in multi-server scenarios. This is the first part of an effort to load balance the backoffice, and by extension, the isolated caches. All this PR does is create a mechanism for us to know if the cache is out of sync; the next part is to be able to synchronize the cache.

Since this can be reviewed as a discrete unit, I've opted to make it its own PR and target a long-lived feature branch.

Testing

Navigate around the backoffice and see that the new cache version table gets created and updated, also try and manually change the version guide to see that the cache is registered as invalid

[bielu]

@nikolajlauridsen if I read it correctly it will check on each request if cache is up to date? I think it would be better to have running background task to do it, as it will not add latency to requests or at least making it switchable from on request to background refresh?