Refactor onWebRTCommCallOpenedEvent

[atsakiridis]

Seems that that right now it is triggered from a couple of places, which don't seem right. Instead, I think we should trigger it from one place: onRtcPeerConnectionIceChangeEvent, called from onicechange and for iceConnectionState == connected.

Just keep in mind this commit, and make sure that there are no audio issues with new logic

[atsakiridis]

Some further notes after doing some coding & testing:

• I tried to remove onWebRTCommCallOpenedEvent from all previous places and introduce it to onRtcPeerConnectionIceChangeEvent for 'connected', but it turns out that there are issues with Firefox which doesn't transition to connected for some reason and hence we never get media
• Tried to leave onWebRTCommCallOpenedEvent only in onRtcPeerConnectionOnAddStreamEvent where it existed previously and this worked without issues
• Still to be consistent with mobile SDKs I think we should try to add it at onRtcPeerConnectionIceChangeEvent but first fix the issues with the state. I think the issue once again might be erroneous STUN/TURN settings

[atsakiridis]

Did some more digging and the issue isn't the STUN/TURN settings. Especially for web the web app needs to know the remote stream at the point where onWebRTCommCallOpenedEvent is called. So we should keep that event in onRtcPeerConnectionOnAddStreamEvent and only there.