Summary:
This diff moves RCTImageLoader, RCTImageEditingManager, and RCTImageStoreManager to CoreModules. This is necessary for us to convert all these NativeModules to TurboModules.
**Note:** As a part of this diff, I had to break apart `RCTImageLoader.h`. All the protocols that were in `RCTImageLoader` are now in their own headers. Furthermore, `RCTImageLoader`'s methods are defined in `RCTImageLoaderProtocol`, so that we can call them from classes like `RCTImageViewManager` in `RCTImage`.
Reviewed By: PeteTheHeat
Differential Revision: D16805827
fbshipit-source-id: 89f6728b0766c30b74e25f7af1be8e6b8a7e6397