WIP: Use Gitaly's RepositoryService.HasLocalBranches RPC

Open username-removed-367626 requested to merge gitaly-has-local-branches into master

What does this MR do?

Use Gitaly's RepositoryService.HasLocalBranches RPC

Are there points in the code the reviewer needs to double check?

No

Why was this MR needed?

https://gitlab.com/gitlab-org/gitaly/issues/630

Does this MR meet the acceptance criteria?

What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitaly/issues/630