Fix widgets getting stuck in loading states (#31314)

* Refer to ClientWidgetApi as "widget API" rather than "messaging"

* Rename StopGapWidgetDriver to ElementWidgetDriver

* Rename StopGapWidget to WidgetMessaging

* Fix WidgetMessaging's lifetime by storing it in WidgetMessagingStore

(Rather than storing just the raw ClientWidgetApi objects.)

* Unfail test

* use an error

* cleanup start

* Add docs

* Prettier

* link to store

* remove a let

* More logging, split up loop

* Add a test demonstrating a regression in Call.start

* Restore Call.start to a single, robust event loop

* Fix test failure by resetting the messaging store

* Expand on the WidgetMessaging doc comment

* Add additional tests to buff up coverage

* Add a test for the sticker picker opening the IM.

* reduce copy paste

---------

Co-authored-by: Half-Shot <will@half-shot.uk>
Co-authored-by: Timo K <toger5@hotmail.de>

test/unit-tests/components/views/voip/CallView-test.tsx

@@ -18,7 +18,6 @@ import {
 } from "matrix-js-sdk/src/matrix";
 import { Widget } from "matrix-widget-api";
 
-import type { ClientWidgetApi } from "matrix-widget-api";
 import {
     stubClient,
     mkRoomMember,
@@ -33,6 +32,7 @@ import { CallView as _CallView } from "../../../../../src/components/views/voip/
 import { WidgetMessagingStore } from "../../../../../src/stores/widgets/WidgetMessagingStore";
 import { CallStore } from "../../../../../src/stores/CallStore";
 import DMRoomMap from "../../../../../src/utils/DMRoomMap";
+import { type WidgetMessaging } from "../../../../../src/stores/widgets/WidgetMessaging";
 
 const CallView = wrapInMatrixClientContext(_CallView);
 
@@ -73,8 +73,11 @@ describe("CallView", () => {
 
         widget = new Widget(call.widget);
         WidgetMessagingStore.instance.storeMessaging(widget, room.roomId, {
+            on: () => {},
+            off: () => {},
             stop: () => {},
-        } as unknown as ClientWidgetApi);
+            embedUrl: "https://example.org",
+        } as unknown as WidgetMessaging);
     });
 
     afterEach(() => {