Element Call video rooms (#9267)

* Add an element_call_url config option

* Add a labs flag for Element Call video rooms

* Add Element Call as another video rooms backend

* Consolidate event power level defaults

* Remember to clean up participantsExpirationTimer

* Fix a code smell

* Test the clean method

* Fix some strict mode errors

* Test that clean still works when there are no state events

* Test auto-approval of Element Call widget capabilities

* Deduplicate some code to placate SonarCloud

* Fix more strict mode errors

* Test that calls disconnect when leaving the room

* Test the get methods of JitsiCall and ElementCall more

* Test Call.ts even more

* Test creation of Element video rooms

* Test that createRoom works for non-video-rooms

* Test Call's get method rather than the methods of derived classes

* Ensure that the clean method is able to preserve devices

* Remove duplicate clean method

* Fix lints

* Fix some strict mode errors in RoomPreviewCard

* Test RoomPreviewCard changes

* Quick and dirty hotfix for the community testing session

* Revert "Quick and dirty hotfix for the community testing session"

This reverts commit 37056514fbc040aaf1bff2539da770a1c8ba72a2.

* Fix the event schema for org.matrix.msc3401.call.member devices

* Remove org.matrix.call_duplicate_session from Element Call capabilities

It's no longer used by Element Call when running as a widget.

* Replace element_call_url with a map

* Make PiPs work for virtual widgets

* Auto-approve room timeline capability

Because Element Call uses this now

* Create a reusable isVideoRoom util

src/components/structures/SpaceRoomView.tsx

@@ -108,8 +108,9 @@ const SpaceLandingAddButton = ({ space }) => {
     const canCreateRoom = shouldShowComponent(UIComponent.CreateRooms);
     const canCreateSpace = shouldShowComponent(UIComponent.CreateSpaces);
     const videoRoomsEnabled = useFeatureEnabled("feature_video_rooms");
+    const elementCallVideoRoomsEnabled = useFeatureEnabled("feature_element_call_video_rooms");
 
-    let contextMenu;
+    let contextMenu: JSX.Element | null = null;
     if (menuDisplayed) {
         const rect = handle.current.getBoundingClientRect();
         contextMenu = <IconizedContextMenu
@@ -145,7 +146,12 @@ const SpaceLandingAddButton = ({ space }) => {
                                 e.stopPropagation();
                                 closeMenu();
 
-                                if (await showCreateNewRoom(space, RoomType.ElementVideo)) {
+                                if (
+                                    await showCreateNewRoom(
+                                        space,
+                                        elementCallVideoRoomsEnabled ? RoomType.UnstableCall : RoomType.ElementVideo,
+                                    )
+                                ) {
                                     defaultDispatcher.fire(Action.UpdateSpaceHierarchy);
                                 }
                             }}