Session migration (#72)

* impl

* retry logic

* simulate

* pass checks

* adjust log level

* retry condition

* fix simulate scenario params

* format

* use `RTCPeerConnectionState` instead of `RTCIceConnectionState`

* adjust retry

* additional check for completer

* more logging

* fix id

* pub

* change package

* doc update

* retry tests

* format

* apply suggestions

lib/src/constants.dart

@@ -2,6 +2,6 @@ class Timeouts {
   static const connection = Duration(seconds: 10);
   static const debounce = Duration(milliseconds: 100);
   static const publish = Duration(seconds: 10);
-  static const iceConnection = Duration(seconds: 10);
+  static const peerConnection = Duration(seconds: 10);
   static const iceRestart = Duration(seconds: 10);
 }