Missing support for 'R' file changes

[nielx]

The format bot crashed on change 7456. The issue is that it does not support the 'R' file change type. This should be added.

2024-03-29 14:29:05 INFO     Starting daemon with timeout set to 300 seconds
2024-03-29 14:29:05 INFO     Starting daemon run
2024-03-29 14:29:05 INFO     Fetching all changes from Gerrit
2024-03-29 14:29:06 INFO     Context for gerrit instance: https://review.haiku-os.org/
2024-03-29 14:29:06 INFO     Found 3 changes
2024-03-29 14:29:06 INFO     Fetching change details for haiku~master~I5c42344b2499bd22581d6b564192decbce937645
Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "/app/formatchecker/runner.py", line 80, in <module>
    daemon_mode(args.timeout, start_date, args.submit)
  File "/app/formatchecker/runner.py", line 58, in daemon_mode
    format_changes(after, submit)
  File "/app/formatchecker/runner.py", line 48, in format_changes
    reformat_change(context, change["id"], change["current_revision"], submit)
  File "/app/formatchecker/core.py", line 35, in reformat_change
    change = context.get_change(change_id, revision_id)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/formatchecker/gerrit.py", line 46, in get_change
    raise RuntimeError("Unsupported file status change")
RuntimeError: Unsupported file status change