Room instances now properly garbage-collected; Firefox publisher offer disabled

Patch Changes

• Disable publisher offer with join in firefox - #1954 (@cnderrauber)

• Fix memory leak where the constructor-registered devicechange listener on navigator.mediaDevices was not removed when a Room was constructed but never connected. The listener kept the Room instance reachable from the global navigator.mediaDevices EventTarget, defeating the FinalizationRegistry cleanup. - #1944 (@nikhilgupta58)

• Ensure that client protocol is set in the dual peer connection case - #1942 (@1egoman)