6aff258c8b
begins implementation of the drive delta tree support by adding boilerplate funcs for getting the backup data, and adding a framework of unit tests that will be used bring testing parity up to par with current tests. --- #### Does this PR need a docs update or release note? - [x] ⛔ No #### Issue(s) * #4689 #### Test Plan - [x] ⚡ Unit test