Implement deletion of asset-library files

Summary:
WIP: Starting point insofar as I'm not sure if there should be an Android equivalent.

My application needs me to delete photos from the photos in iOS.

I have tested this in my application and it works, have a screenshot from iOS asking as well and it does successfully delete the photos from the global Photos app.

Related to facebook/react-native#15253, it kind of continues using the deprecated assets-library framework, but that does need (and will be an bigger and bigger issue coming up) of assets-library URLs being used.

I also assume RN prefers error handling at the JS level? Are the URLs starting with `asset-library`, etc.
Closes facebook/react-native#15481

Differential Revision: D6438016

Pulled By: hramos

fbshipit-source-id: 47512140f62f458c14ad2ade2b358846e168c964

CameraRoll.js

@@ -133,6 +133,10 @@ class CameraRoll {
     return this.saveToCameraRoll(tag, 'photo');
   }
 
+  static deletePhotos(photos: Array<string>) {
+    return RCTCameraRollManager.deletePhotos(photos);
+  }
+
   /**
    * Saves the photo or video to the camera roll / gallery.
    *