Move thread last seen logic to fully config based

[SessionHero01]

This PR moves most of the thread data into config based system, basically now we'll do this:

1. lastSeen is managed fully by the config system, the thread table no longer needs to keep in sync with this
2. Count unread messages based on the config's last seen when querying threads
3. Automatically handling the messages being marked as read (sending receipt, starting expiration timer, etc), is now done automatically by listening to config changes
4. Add isOutgoing virtual column to sms/mms database so we don't have to do the crazy bitmasking stuff
5. No need to call threadDb.update anymore: now every piece of data is computed using latest data