We still rely on the Dirty API for project rename (before/after) values,
but we don't access the dirty api from the service class anymore.
The previous value is now part of the initialization, which makes it
easier to test and the behavior is clearer.
The same was done with the `rename_repo` on the Storage classes, we now
provide before and after values as part of the method signature.
Direct disk access is done through Gitaly now, so the legacy path was
deprecated. This path was used in Gitlab::Shell however. This required
the refactoring in this commit.
Added is the removal of direct path access on the project model, as that
lookup wasn't needed anymore is most cases.
Closes https://gitlab.com/gitlab-org/gitaly/issues/1111
