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

example/pubspec.lock

@@ -50,6 +50,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "3.0.1"
+  csslib:
+    dependency: transitive
+    description:
+      name: csslib
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.17.1"
   dart_webrtc:
     dependency: transitive
     description:
@@ -84,7 +91,7 @@ packages:
       name: device_info_plus_platform_interface
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.3.0"
+    version: "2.3.0+1"
   device_info_plus_web:
     dependency: transitive
     description:
@@ -184,6 +191,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.2.0"
+  html:
+    dependency: transitive
+    description:
+      name: html
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.15.0"
   http:
     dependency: transitive
     description:
@@ -338,13 +352,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "3.1.0"
-  platform_detect:
-    dependency: transitive
-    description:
-      name: platform_detect
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.3"
   plugin_platform_interface:
     dependency: transitive
     description:
@@ -373,13 +380,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "6.0.2"
-  pub_semver:
-    dependency: transitive
-    description:
-      name: pub_semver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.0"
   shared_preferences:
     dependency: "direct main"
     description:
@@ -497,6 +497,20 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.3.0"
+  universal_html:
+    dependency: transitive
+    description:
+      name: universal_html
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.8"
+  universal_io:
+    dependency: transitive
+    description:
+      name: universal_io
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.4"
   uuid:
     dependency: transitive
     description:
@@ -511,6 +525,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.1.1"
+  web_browser_detect:
+    dependency: transitive
+    description:
+      name: web_browser_detect
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.2"
   webrtc_interface:
     dependency: transitive
     description: