Remove LegacyCallHandler singleton (#34086)

* Remove dead code

* Remove LegacyCallHandler singleton

Route via SDKContext to cut import cycles

* Remove unused setting

* Fix tests

* Fix tests

* Cascade SDKContext through PersistedElement

* Improve coverage

* Iterate

* Improve coverage

* Improve coverage

apps/web/src/components/structures/MatrixChat.tsx

@@ -95,7 +95,6 @@ import SoftLogout from "./auth/SoftLogout";
 import { copyPlaintext } from "../../utils/strings";
 import { PosthogAnalytics } from "../../PosthogAnalytics";
 import { initSentry } from "../../sentry";
-import LegacyCallHandler from "../../LegacyCallHandler";
 import { showSpaceInvite } from "../../utils/space";
 import { type ButtonEvent } from "../views/elements/AccessibleButton";
 import { type ActionPayload } from "../../dispatcher/payloads";
@@ -695,7 +694,7 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
                 }
                 break;
             case "logout":
-                LegacyCallHandler.instance.hangupAllCalls();
+                this.stores.legacyCallHandler.hangupAllCalls();
                 Promise.all([...[...CallStore.instance.connectedCalls].map((call) => call.disconnect())]).finally(() =>
                     Lifecycle.logout(this.stores.oidcClientStore),
                 );