Widgets could persist forever because they were still sticky when we end the messaging.
Ending the messaging emits an event to which we connect ui changes that move the widget out of the screen. It does not end up in a pip view however.

So we need to make sure the widget is not persistend anymore when we call `stopMessagingByUid` so that any dom changes that remove the AppTile happen when the widget is not persistend anymore and let it destroy.

This PR also makes the role for `MatrixRTCSessionManager` more strict. We do ONLY use it in `Call.ts` and `CallStore`  so that we dont end up in reaces where we updated the ui based on the session manager but not in sync with the call and callstore changes.

Rename activeCalls to connectedCalls. Active call can also be understood as a call where there are active participants but the user itself is not connected. Especially with the `hasActiveCallSession` field of the useRoomCall hook which is tracking active (not necassarly connected sessions)