Make the js-sdk compatible with MSC preferred foci and active focus. (#4195)

* Refactor to preferred and active foci.

Signed-off-by: Timo K <toger5@hotmail.de>

* make the sdk compatible with MSC4143 but still be backwards compatible

* comment fixes

* also fallback to legacy if the current member event is legacy

* use XOR types

* use EitherAnd

* make livekit Foucs types simpler

* review

* fix tests

* test work

* more review + more tests

* remove unnecassary await that is in conflict with the comment

* make joinRoomSession sync

* Update src/matrixrtc/MatrixRTCSession.ts

Co-authored-by: Andrew Ferrazzutti <af_0_af@hotmail.com>

* review

* fix

* test

* review

* review

* comment clarification

* typo

---------

Signed-off-by: Timo K <toger5@hotmail.de>
Co-authored-by: Andrew Ferrazzutti <af_0_af@hotmail.com>

spec/unit/matrixrtc/MatrixRTCSessionManager.spec.ts

@@ -35,6 +35,7 @@ const membershipTemplate: CallMembershipData = {
     device_id: "AAAAAAA",
     expires: 60 * 60 * 1000,
     membershipID: "bloop",
+    foci_active: [{ type: "test" }],
 };
 
 describe("MatrixRTCSessionManager", () => {