osd/scrub: separate between PG state flags and internal scrubber operation

osd/scrub: separate between PG state flags and internal scrubber operation

Modify the scrubber to rely on internal flags for 'should we repair' and
'is this a deep scrub', instead of using PG_STATE_REPAIR & PG_STATE_DEEP_SCRUB.

This enables us to implement the 'fix-as-you-go deepscrub' functionality
of 'osd_scrub_auto_repair', without displaying REPAIR status to the user.

Fixes: https://tracker.ceph.com/issues/50446
Signed-off-by: Ronen Friedman <rfriedma@redhat.com>
Co-Authored by: Neha Ojha <nojha@redhat.com>