Add custom audio renderer for iPhone earpiece and only render joined participants (#3249)

* Add custom audio renderer to only render joined participants & add ios earpice workaround

fix left right to match chromium + safari
(firefox is swapped)

earpice as setting

Simpler code and documentation
The doc explains, what this class actually does and why it is so complicated.

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

use only one audioContext, remove (non working) standby fallback

* Add tests

* use optional audio context and effect to initiate it + review

src/room/MuteStates.test.tsx

@@ -79,6 +79,7 @@ function mockDevices(available: Map<string, DeviceLabel>): MediaDevice {
     selectedId: "",
     selectedGroupId: "",
     select: (): void => {},
+    useAsEarpiece: false,
   };
 }