TAP Backfill should send persisted deletions to the brand-new master or replica node to support XDCR

If the destination node needs to receive the TAP backfill from the source node, it has to receive the persisted deletions from the source node as well, to support the XDCR. Couchstore supports to retrieve persisted deletions. The ep-engine in the source node should retrieve the list of all persisted deletions as part of backfill.