BREAKING CHANGE: Update API for connection, communication channel state and is browser value (#14)

* refactor(lib, example, example_full): use streams for communication channel and is ios browser

* feat: add abstract toJson() to message

* refactor: add deprecations for nearby_service

* feat(example): update main.dart

* feat(nearby_service): add comments

* feat(nearby_service_platform_interface): add deprecation to getConnectedDeviceStream

* feat(nearby_service/message): add concrete implementation for toJson()

* feat(nearby_service/android): add deprecations

* fix(nearby_service/android): reset check for android device

* fix(nearby_service/ios): change ios service to deprecations variant

* chore(nearby_service): edit deprecation messages

* chore: update gitignore

* doc: add CONTRIBUTING file

* doc: update CONTRIBUTING file

* chore: update CONTRIBUTING.md

* chore: update CONTRIBUTING.md

* chore: version 0.1.0

* fix(example_full): move startListeningCommunicationChannelState() upper

lib/nearby_service_method_channel.dart

@@ -54,13 +54,17 @@ class MethodChannelNearbyService extends NearbyServicePlatform {
   }
 
   @override
+  @Deprecated('Use getConnectedDeviceStreamById instead')
   Stream<NearbyDevice?> getConnectedDeviceStream(NearbyDevice device) {
+    return getConnectedDeviceStreamById(device.info.id);
+  }
+
+  @override
+  Stream<NearbyDevice?> getConnectedDeviceStreamById(String deviceId) {
     const connectedDeviceChannel = EventChannel(
       "nearby_service_connected_device",
     );
-    return connectedDeviceChannel
-        .receiveBroadcastStream(device.info.id)
-        .map((e) {
+    return connectedDeviceChannel.receiveBroadcastStream(deviceId).map((e) {
       final updatedResult = ResultHandler.instance.handle(e);
       return NearbyDeviceMapper.instance.mapToDevice(updatedResult);
     });