Added new locking APIs for the rbd component named
`rbd_lock_acquire`, `rbd_lock_break`, `rbd_lock_release`, `rbd_lock_get_owners`,
`rbd_is_exclusive_lock_owner` along with supporting TCs.
Fixes: #275
Signed-off-by: Nikhil-Ladha <nikhilladha1999@gmail.com>