feat: Make Frame Processor Plugins object-oriented on iOS as well (#1496)

* feat: Make Frame Processor Plugins object-oriented on iOS as well

* Add Plugin in AppDelegate

example/ios/VisionCameraExample/AppDelegate.mm

@@ -1,6 +1,8 @@
 #import "AppDelegate.h"
 
 #import <React/RCTBundleURLProvider.h>
+#import "VisionCameraExample-Swift.h"
+#import <VisionCamera/FrameProcessorPlugin.h>
 
 @implementation AppDelegate
 
@@ -10,6 +12,8 @@
   // You can add your custom initial props in the dictionary below.
   // They will be passed down to the ViewController used by React Native.
   self.initialProps = @{};
+  
+  [FrameProcessorPlugin registerPlugin:[[ExamplePluginSwift alloc] init]];
 
   return [super application:application didFinishLaunchingWithOptions:launchOptions];
 }