Limit git repository sync to specific branch and revision

[gnunn1]

The gitea operator has the very useful ability to sync with other git respositories. It would be very useful to be able to have more control over this sync in terms of what branches to sync and to sync only to a specific revision.

The ability to sync to a specific revision enables using GitOps in RHDP and managing the RHDP environments via commit pinning, i.e. Dev is at HEAD, test is at commit xxxxx and prod is at commit yyyyy.