Prepare for Element Call integration (#9224)

* Improve accessibility and testability of Tooltip

Adding a role to Tooltip was motivated by React Testing Library's
reliance on accessibility-related attributes to locate elements.

* Make the ReadyWatchingStore constructor safer

The ReadyWatchingStore constructor previously had a chance to
immediately call onReady, which was dangerous because it was potentially
calling the derived class's onReady at a point when the derived class
hadn't even finished construction yet. In normal usage, I guess this
never was a problem, but it was causing some of the tests I was writing
to crash. This is solved by separating out the onReady call into a start
method.

* Rename 1:1 call components to 'LegacyCall'

to reflect the fact that they're slated for removal, and to not clash
with the new Call code.

* Refactor VideoChannelStore into Call and CallStore

Call is an abstract class that currently only has a Jitsi
implementation, but this will make it easy to later add an Element Call
implementation.

* Remove WidgetReady, ClientReady, and ForceHangupCall hacks

These are no longer used by the new Jitsi call implementation, and can
be removed.

* yarn i18n

* Delete call map entries instead of inserting nulls

* Allow multiple active calls and consolidate call listeners

* Fix a race condition when creating a video room

* Un-hardcode the media device fallback labels

* Apply misc code review fixes

* yarn i18n

* Disconnect from calls more politely on logout

* Fix some strict mode errors

* Fix another updateRoom race condition

test/stores/VoiceRecordingStore-test.ts

@@ -38,21 +38,27 @@ describe('VoiceRecordingStore', () => {
         [room3Id]: undefined,
     };
 
+    const mkStore = (): VoiceRecordingStore => {
+        const store = new VoiceRecordingStore();
+        store.start();
+        return store;
+    };
+
     describe('startRecording()', () => {
         it('throws when roomId is falsy', () => {
-            const store = new VoiceRecordingStore();
+            const store = mkStore();
             expect(() => store.startRecording(undefined)).toThrow("Recording must be associated with a room");
         });
 
         it('throws when room already has a recording', () => {
-            const store = new VoiceRecordingStore();
+            const store = mkStore();
             // @ts-ignore
             store.storeState = state;
             expect(() => store.startRecording(room2Id)).toThrow("A recording is already in progress");
         });
 
         it('creates and adds recording to state', async () => {
-            const store = new VoiceRecordingStore();
+            const store = mkStore();
             const result = store.startRecording(room2Id);
 
             await flushPromises();
@@ -64,7 +70,7 @@ describe('VoiceRecordingStore', () => {
 
     describe('disposeRecording()', () => {
         it('destroys recording for a room if it exists in state', async () => {
-            const store = new VoiceRecordingStore();
+            const store = mkStore();
             // @ts-ignore
             store.storeState = state;
 
@@ -74,7 +80,7 @@ describe('VoiceRecordingStore', () => {
         });
 
         it('removes room from state when it has a recording', async () => {
-            const store = new VoiceRecordingStore();
+            const store = mkStore();
             // @ts-ignore
             store.storeState = state;
 
@@ -84,7 +90,7 @@ describe('VoiceRecordingStore', () => {
         });
 
         it('removes room from state when it has a falsy recording', async () => {
-            const store = new VoiceRecordingStore();
+            const store = mkStore();
             // @ts-ignore
             store.storeState = state;