Implement https://github.com/vector-im/element-web/issues/18957 following requirements:
* Create a new right panel view to list all the threads in a given room.
* Change ThreadView previous phase to be ThreadPanel rather than RoomSummary
* Implement local filters for My and All threads
In addition:
* Create a new TileShape for proper rendering requirements (hiding typing indicator)
* Create new timelineRenderingType for proper rendering requirements
Extreme confusion between users and members, and presumably we were
passing one as the other and they were similar enough that it
worked.
UserView still makes fake member objects but this at least fixes
the user view in the right panel.
Fixes https://github.com/vector-im/element-web/issues/19158
