gitserver: Add MigrateFrom attribute to support repo migration
Created by: indradhanush
Fixes #26490 (closed).
In this commit, by adding MigrateFrom to protocol.RepoUpdateRequest and server.cloneOptions.RepoUpdateRequest, we are enabling gitserver to be able to distinguish between two types of clone requests:
-
Regular repo clones (the current norm)
-
A migration based repo clone - where we clone the repo from another gitserver instead of the upstream repo URL of the external service.
No tests at this point. A subsequent PR for #26491 (closed) should have some once this functionality is consumed.