Podspec and sample integration

Summary: Create podspec for UI Debugger and integrate with our iOS sample application.

Reviewed By: aigoncharov

Differential Revision: D47715973

fbshipit-source-id: a64444660ea9fb8a2c29fcafe1a44266e8daf414

iOS/Plugins/FlipperKitUIDebuggerPlugin/FlipperKitUIDebuggerPlugin/FlipperKitUIDebuggerPluginInit.mm

@@ -13,6 +13,10 @@
 #import "UIDDescriptorRegister.h"
 #import "UIDTreeObserverFactory.h"
 
+@interface FlipperKitUIDebuggerPlugin ()
+- (instancetype)initWithContext:(UIDContext*)context;
+@end
+
 #ifdef __cplusplus
 extern "C" {
 #endif