This prevents RoomView from doing any peeking whilst the join/registration is in progress, causing weirdness with TimelinePanel getPendingEventList (which throws an error if called when peeking).

These must now make a dispatch to RoomViewStore instead of calling `viewRoom` directly on MatrixChat. This will call both `viewRoom` of MatrixChat _and_ the logic in RVS so there is some redundancy here. It'd be best to move as much as possible of viewRoom out to the RVS itself.

But for now, this fixes a bug that occures when leaving (the viewed room would not change).

This prevents leaking of state that we do not want to share with the next user