refactor SyncParticipants and updatePowerLevelsAndJoinRule to
set power levels and join rule in initial state
sync pending/requesting/banned members on room creation
bridge room creation with actual group creator, if known
support identifying logged-in users by PNI
support for group invites, accepting or rejecting invites
changed SourceACI to SourceServiceID; PNI type SourceServiceIDs seem to exist - not sure why.
Some oddities: if the group creation is double-puppeted, the bridge bot will say "Hi, I'm a Signal bridge bot". Not sure how to turn that off. Group creation by ghost is not a problem
Sometimes the bridge bot will double down on group creation invites
Some oddities: if the group creation is double-puppeted, the bridge bot will say "Hi, I'm a Signal bridge bot". Not sure how to turn that off. Group creation by ghost is not a problem Sometimes the bridge bot will double down on group creation invites