Limit the number of connections per repository

[madadam]

Currently we try to connect to every peer sharing a given repository that we know of. This can become a problem for very popular repositories which can have thousands of replicas. There should be a upper limit (ideally user configurable but with sensible default) for the number of connections per repository.

[IvanaBlzvc]

https://redmine.equalit.ie/issues/31633