This generic swh cli should be done so that is minimal dependency installed especially for "pure client" commands (e.g. swh.deposit's deposit or swh.model's identify tools).

A possible way of doing such a thing is to have a master swh command declared in this package as the main entry point: the swh command group (using click) which defines a few very command command line options (like --log-level), and a mechanism to load installed SWH cli plugins via setuptools' pkg_resources

This also requires we can install only a very light base version of swh.core (typically without db or aiohttp/flask dependencies).