Selecting an object from Edit mode

When in Edit-mode for one picture, to let the user choose a different picture without exiting Edit-mode, we can use the same SelectObject input action we used in Main-mode. In fact, the code is mostly the same. Open the EditPictureMode script for editing and make the following changes:

1. We're going to listen for Input System events, so to begin, we need to add a using statement for that namespace. Ensure the following line is at the top of the file:

   using UnityEngine.InputSystem;

2. Add a private camera variable at the top of the class and initialize it in Start:

       Camera camera;
       void Start()
       {
           camera = Camera.main;
       }

3. The OnSelectObject action listener will call FindObjectToEdit. Like in GalleryMainMode, it does a Raycast on the PlacedObjects layer. But now, we must check whether it has hit an...