* Avoid destroying calls until they are hidden from the UI
We often want calls to exist even when no more participants are left in the MatrixRTC session. So, we should avoid destroying calls as long as they're being presented in the UI; this means that the user has an intent to either join the call or continue looking at an error screen, and we shouldn't interrupt that interaction.
The RoomViewStore is now what takes care of creating and destroying calls, rather than the CallView. In general it seems kinda impossible to safely create and destroy model objects from React lifecycle hooks, so moving this responsibility to a store seemed appropriate and resolves existing issues with calls in React strict mode.
* Wait for a close action before closing a call
This creates a distinction between the user hanging up and the widget being ready to close, which is useful for allowing Element Call to show error screens when disconnected from the call, for example.
* Don't expect a 'close' action in video rooms
These use the returnToLobby option and are expected to remain visible when the user leaves the call.
* Fix tiny typo in existing code
* Create a hook that uses the right panel store
So that we track changes to the right panel phases
* Create a context that wraps the previous hook we created
We do this so that we can get by using a single event listener i.e we
only need to call `useCurrentPhase` in the provider as opposed to
calling it in each header icon.
* Create a hook that tells you if a panel is open or not
* Create component that wraps Icon
and adds a class name when the corresponding panel is open
* Style room header icons for when they are toggled
* Style face pile for toggle state
* Fix broken CI
* Give directory a better name
* Update year in license
* Use a stronger type
