Adding FetchHttpRemote RPC and messages
FetchHttpRemote will add a remote, and fetch the remote to a repository.
This is something @jacobvosmaer-gitlab and I discussed, to consolidate the fetch logic from the geo ruby code into gitaly.
This RPC will also get called by the "GeoFastInitialFetch" RPC.
corresponding RPC mr: gitaly!1126 (merged)
Edited by John Cai