cli: make the deposit cli command a subcommand of the main 'swh' one
'swh' being the new master command group (defined in swh.core); so:
swh deposit --help
works. The 'admin' (deposit server management) is only available if the swh.deposit[server] optional package is installed.
Ensure the 'swh-deposit' still works for now.
also rename the 'deposit' subcommand as 'upload' to prevent the ugly 'swh deposit deposit' in favor of:
swh deposit upload
Depends on swh-core!56 (closed). Related to swh-core#1671.
Migrated from D1428 (view on Phabricator)