Add "module" post-write hook

Add "module" post-write hook

This hook type is almost identical to the console_scripts hook, except
it's running `python -m black` instead of using black's console_script.

It is mainly useful for tools without console scripts (e.g. ruff), but
has semantics closer to the console_scripts hook in that it finds the
ruff module available to the running interpreter instead of finding
an executable by path.

Pull request courtesy Frazer McLean.

Fixes: #1686
Closes: #1687
Pull-request: https://github.com/sqlalchemy/alembic/pull/1687
Pull-request-sha: 54d29c34642d88e88ab29e46fa4022d227f8aa60
Change-Id: I804a1a7d3f6423ba23bc556b7f4024c401a8787e