os/bluestore: set rocksdb iterator bounds for Bluestore::_collection_list()

os/bluestore: set rocksdb iterator bounds for Bluestore::_collection_list()

When Bluestore::_collection_list() is called during PG removal, rocksdb
often has to iterate over many rocksdb deletion tombstones from recenently
deleted onode keys. This change bounds the rocksdb iteration when possible,
to avoid high latencies caused by iteration over many contiguous deletion
tombstones.

Fixes: https://tracker.ceph.com/issues/58274
Signed-off-by: Cory Snyder <csnyder@iland.com>
(cherry picked from commit a6bcb577c6626afa226ac63f068cb7287c3042b4)