osd/: mechanically rename RecoveryMachine/State/Ctx to Peering*

osd/: mechanically rename RecoveryMachine/State/Ctx to Peering*

I'm going to extract this logic and reuse it in crimson.  Recovery* has
always been a confusing name as it implements neither log-based recovery
nor backfill.  Rather, it's mainly the buisiness logic for agreeing on
an authoritative log and some ancillary things such as scrub/backfill
reservation.

$ for i in $(git grep -l 'RecoveryMachine'); do sed -i 's/RecoveryMachine/PeeringMachine/g' $i; done
$ for i in $(git grep -l 'RecoveryState'); do sed -i 's/RecoveryState/PeeringState/g' $i; done
$ for i in $(git grep -l 'RecoveryCtx'); do sed -i 's/RecoveryCtx/PeeringCtx/g' $i; done

Signed-off-by: Samuel Just <sjust@redhat.com>