mgr/volumes: evict clients based on auth ID and subvolume mounted
In manila, when an auth ID is denied access to a subvolume the auth ID's caps are suitably removed, and the clients that have mounted the subvolume using the auth ID are immediately evicted, denying access to the subvolume.
The mgr-volumes CLI could look like,
`fs subvolume evict <volname> <subvolname> <auth name> [--group_name <group_name>]`
$ ceph fs subvolume evict cephfs manila-share-00 client.bob --group_name manila-share-group-00