crimson/osd/pg: Let PGListener use start_peering_event_operation

crimson/osd/pg: Let PGListener use start_peering_event_operation

PG::start_peering_event_operation is a template function while
PGRecovery::pg is of PGRecoveryListener* type. We can't expose a template
function through the PGRecoveryListener interface since it must be
also virtual.
Instead, introduce start_peering_event_operation_listener which will act
as a wrapper to PG::start_peering_event_operation for PGRecovery to use
freely.

Signed-off-by: Matan Breizman <mbreizma@redhat.com>
(cherry picked from commit c94e604bbb6550109ad5945ab86f82d6d5aeb1a1)