adds the primary `debug` command to the cli as
a hidden command option. Also includes the scaffold for
a `metadata-files` command that could be used to print
out the metadata files in the backup.
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#### Does this PR need a docs update or release note?
- [x] ⛔ No
#### Type of change
- [x] 🌻 Feature
#### Test Plan
- [x] ⚡ Unit test
