Tech debt: Update method used to get recent calls list

### Your use case

We currently still fetch the recent calls list using the old GroupCall class. We should update it to something more MatrixRTC-y, although the semantics are room that has an m.call event (ie. that has the state event to say it has a call ongoing). This concept doesn't exist now, so the semantics will need to change slightly.

Ideas we have:
* Just make it show all your rooms
* Show rooms that have any call member events in (ie. ones that a call has ever taken place in)
* Mark our rooms as video rooms and show all video rooms
* Mark them in some way in account data like DM rooms

Since you can only join calls in the SPA anyway, and can't use your regular account, there's no practical difference as it stands currently. This would only affect things once we allowed federation / had people logging in with accounts used for things other than EC.

### Have you considered any alternatives?

_No response_

### Additional context

_No response_