add information about active scrubs to "ceph -s" (and elsewhere)
currently, there is no way to track scrubs operations on a filesystem expect to check the mds log and figure out which ones have completed/pending (since multiple scrub operations can be triggered on subpaths).
It would be helpful if the active scrub operations are shown in ceph status output. Sample output can be:
MDS.<daemonID> scrubbing in progress: scrub_path <path_that_is_scrubbed> recursive repair
MDS.<daemonID> scrubbing in progress: scrub_path <different_path_that_is_scrubbed> recursive repair
This would especially simplify situations when multiple scrub_path commands were started or with large cephfs.