R1:ab2aa74d6e29

Fix several duplication/replay behaviors in Aphlict

Summary:
Ref T12566. Ref T12563. This fixes three bugs with Aphlict replay stuff:

First, Conphernece would try to repaint the UI even if no thread was open. Only repaint when a thread is open.

Second, although we deduplicate JX.Leader messages, we didn't deduplicate actual notification messages. If you browsed the leader window, then it re-elected itelf as a leader and replayed history, it could rebroadcast notifications and other windows could show…