Support using Element Call for voice calls in DMs (#30817)

* Add voiceOnly options.

* tweaks

* Nearly working demo

* Lots of minor fixes

* Better working version

* remove unused payload

* bits and pieces

* Cleanup based on new hints

* Simple refactor for skipLobby (and remove returnToLobby)

* Tidyup

* Remove unused tests

* Update tests for voice calls

* Add video room support.

* Add a test for video rooms

* tidy

* remove console log line

* lint and tests

* Bunch of fixes

* Fixes

* Use correct title

* make linter happier

* Update tests

* cleanup

* Drop only

* update snaps

* Document

* lint

* Update snapshots

* Remove duplicate test

* add brackets

* fix jest

test/unit-tests/toasts/IncomingCallToast-test.tsx

@@ -188,6 +188,7 @@ describe("IncomingCallToast", () => {
                 room_id: room.roomId,
                 skipLobby: true,
                 view_call: true,
+                voiceOnly: false,
             }),
         );
         await waitFor(() =>
@@ -215,6 +216,7 @@ describe("IncomingCallToast", () => {
                 room_id: room.roomId,
                 skipLobby: false,
                 view_call: true,
+                voiceOnly: false,
             }),
         );
         await waitFor(() =>
@@ -239,6 +241,7 @@ describe("IncomingCallToast", () => {
                 room_id: room.roomId,
                 skipLobby: true,
                 view_call: true,
+                voiceOnly: false,
             }),
         );
         await waitFor(() =>