Extend ListRefs to replace specialized RPCs
We've got a bunch of RPCs which can easily be replaced by ListRefs if we extend ListRefs:
- FindAllBranchNames can already be converted. The only difference is that ListRefs returns both reference name and its object ID, but this should not be a performance concern.
- FindAllTagNames can be replaced the same as FindAllBranchNames.
- FindAllBranches can be replaced when we add a new option to list merged branches.
- FindAllRemoteBranches can be replaced when we add the ability to have ListRefs return parsed commits.
- ListBranchNamesContaining can be replaced when we add a new option to only list branches containing a specific commit.
- ListTagNamesContaining can be replaced the same as ListBranchNamesContaining.