Adds a CTA on the room list to view invites if there are any.
The invite list presents each invite with accept/decline buttons
and (for room invites) the sender details.
Fixes#102
* Implement room member list
* Move timeline initialization back to `TimelinePresenter`.
* Fix crash when the `innerRoom` inside a `RustMatrixRoom` is destroyed but `syncUpdateFlow` is still running.
* Address review comments