Implement react-native-flipper on iOS (#795)

Summary:
Implement the react-native-flipper native module on iOS. Uses very similar abstractions as on Android.

## Changelog

[react-native-flipper] Support iOS
Pull Request resolved: https://github.com/facebook/flipper/pull/795

Test Plan:
Tested using the RN TicTacToe example app

{F228406333}

Reviewed By: mweststrate

Differential Revision: D19853017

Pulled By: priteshrnandgaonkar

fbshipit-source-id: d93d35ff984b9ba75f812c4c8e3c82e4d550f0c0

iOS/FlipperKit/FlipperConnection.h

@@ -28,4 +28,9 @@ plugin with a matching identifier.
 */
 - (void)receive:(NSString *)method withBlock:(SonarReceiver)receiver;
 
+/**
+Report an error to the Flipper desktop app
+*/
+- (void)errorWithMessage:(NSString *)message stackTrace:(NSString *)stacktrace;
+
 @end