Implement DestructibleInterface on GitLFS refs
Summary: Ref T7789. Make sure these get cleaned up when a repository is destroyed.
- Created a new repository.
- Pushed some LFS data to it.
- Used bin/remove destroy to nuke it.
- Verified the LFS stuff was cleaned up and the underlying files were destroyed (SELECT * FROM repository_gitlfsref, etc).
Reviewed By: chad
Maniphest Tasks: T7789
Differential Revision: https://secure.phabricator.com/D15493