osd/: move most peering state to PeeringState

osd/: move most peering state to PeeringState

This patch moves the 40 something peering state variables over into
PeeringState while leaving references to them in PG.  The following
patches will move over the users until all users are in PeeringState.
Then, the PG references will be removed.  A subsequent patch will also
move the recovery_state member to be the last initialize and first
destructed.

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