debian: package mgr/smb in ceph-mgr-modules-core

debian: package mgr/smb in ceph-mgr-modules-core

The `BaseController` auto-imports the packaged `mgr/dashboard/controllers/smb.py`
file, which in turn wants to import `smb.enums` etc. which is part of the `smb`
package which is missing from `debian/ceph-mgr-modules-core.install`, thus
missing in the package. The missing module causes an exception
`ModuleNotFoundError: No module named 'smb'` on mgr instances when running a
ceph tentacle cluster installed from debian packages.

See: https://tracker.ceph.com/issues/74268
Signed-off-by: Roland Sommer <rol@ndsommer.de>