Ability to specify reference repository

[Vampire]

If you have a clone of a repository locally, you can currently use local.git.foo to use that current worktree instead, ignoring configured branch or tag.
It would be nice to have an alternative possibility like local.gitreference.foo or similar, that would then be used for the --reference option of git-clone, so that the object store of that local repository can be reused while still using the configured branch or tag.