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

pubspec.lock

@@ -57,6 +57,13 @@ 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: "direct main"
     description:
@@ -163,6 +170,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.8.1"
+  html:
+    dependency: transitive
+    description:
+      name: html
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.15.0"
   http:
     dependency: "direct main"
     description:
@@ -282,13 +296,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "3.1.0"
-  platform_detect:
-    dependency: "direct main"
-    description:
-      name: platform_detect
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.3"
   plugin_platform_interface:
     dependency: transitive
     description:
@@ -310,13 +317,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.0.1"
-  pub_semver:
-    dependency: transitive
-    description:
-      name: pub_semver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.0"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -385,6 +385,20 @@ 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: "direct main"
     description:
@@ -399,6 +413,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.1.1"
+  web_browser_detect:
+    dependency: "direct main"
+    description:
+      name: web_browser_detect
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.2"
   webrtc_interface:
     dependency: transitive
     description:
@@ -412,7 +433,7 @@ packages:
       name: win32
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.3.4"
+    version: "2.3.6"
   xdg_directories:
     dependency: transitive
     description: