ReplicatedPG::mark_all_unfound_lost: delete local copy if necessary

There might be a local copy for an EC pool in the DELETE case.  The replica
copies should be already handled by merge_log.

Fixes: #7439
Signed-off-by: Samuel Just <sam.just@inktank.com>
RepilcatedPG: handle ec pools in pick_newest_available

Fixes: #7439
Signed-off-by: Samuel Just <sam.just@inktank.com>
PG::PriorSet: consider lost osds in up_now for pcontdec

Otherwise, the pg will remain down even as osds are marked lost.

Signed-off-by: Samuel Just <sam.just@inktank.com>