Rename GroupCallView to CallView, and fold ElementCallView into it

Three layers stood between a shell and the call: `ElementCall` (the
component), `ElementCallView` and `GroupCallView`. The middle one only
held the `joined` flag and the mute state, both of which nothing outside
the call reads any more, so it is folded into the view it wrapped. That
view is now `CallView`, since "group call" is a name from before
Element Call handled anything else.

Its docstring says what it is: the whole lifecycle of a call — lobby,
the call itself, and what comes after — with the lobby and the post-call
screen each present or skipped depending on the parameters and the host.
Both the standalone RoomPage and the component render it directly.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

component/index.tsx

@@ -51,7 +51,7 @@ import { shouldPolyfill as shouldPolyfillSegmenter } from "@formatjs/intl-segmen
 import { shouldPolyfill as shouldPolyfillDurationFormat } from "@formatjs/intl-durationformat/should-polyfill.js";
 
 import EN from "../locales/en/app.json";
-import { ElementCallView } from "../src/ElementCallView";
+import { CallView } from "../src/room/CallView";
 import { ErrorPage } from "../src/FullScreenView";
 import { ClientProvider } from "../src/ClientContext";
 import { HostBridgeProvider } from "../src/HostBridge";
@@ -269,7 +269,7 @@ export const ElementCall: FC<ElementCallProps> = ({
                           <ClientProvider client={client}>
                             <MediaDevicesContext value={mediaDevices}>
                               <ProcessorProvider>
-                                <ElementCallView
+                                <CallView
                                   client={client}
                                   rtcSession={rtcSession}
                                   isPasswordlessUser={false}