High-level workflow:

1. Find the last txnTable noop oplog entry (T1) before stableOpTime (T2). This could be non-existent if we have never written down a noop.
2. Scan oplog in (T1, T2], to restore the in-memory transaction table upto stable opTime T2.
3. As part of the normal replication recovery which applies oplog entries (T2, truncateAfterPoint], restore the in-memory transaction table to latest.

Notes:

1. Maybe it's possible to record the opTime of the last txnTable noop oplog entry before stableOpTime in a local collection to accelerate the first step.
2. Clean shutdown should write a noop right before shutdown so that we don't need to apply any oplog entry during startup. This should be handled either in this ticket or SERVER-100343.