Add basic creation / entering tests for group calls (#2575)

* Add basic creation / entering tests for group calls

* Missing space

Co-authored-by: Robin <robin@robin.town>

* Assert more of the group call member event

and also move call leaving to a finally so it doesn't leaving a call
hagning if it fails.

Co-authored-by: Robin <robin@robin.town>

spec/test-utils/webrtc.ts

@@ -58,9 +58,13 @@ class MockMediaStreamAudioSourceNode {
     connect() {}
 }
 
+class MockAnalyser {
+    getFloatFrequencyData() { return 0.0; }
+}
+
 export class MockAudioContext {
     constructor() {}
-    createAnalyser() { return {}; }
+    createAnalyser() { return new MockAnalyser(); }
     createMediaStreamSource() { return new MockMediaStreamAudioSourceNode(); }
     close() {}
 }
@@ -154,4 +158,5 @@ export class MockMediaHandler {
     }
     stopUserMediaStream() { }
     hasAudioDevice() { return true; }
+    stopAllStreams() {}
 }