Add Gitty authentication cache

Gitty server is requesting authorization to Nuxeo nodes for each git requests.

Authorization resolution is "heavy" as it requires a directory session plus a core session to be resolved.

As seen in NXCONNECT-2159, during package resolution we require are doing a lot of requests against Gitty to resolve package dependencies which lead to most of the time spend in networking IO.

By adding a short time-based cache on user rights, we could prevent half of the requests done during that load.