Command pattern (Undo/Redo) system began. (Read desc)

I spent about 6 hours trying to fix this one specific bug involving the move undo. Turns out all I had to do was calm down and think logically instead of typing random bullshit for a few hours until it worked. I'm tired and I thank this for ruining my sleep schedule.

Assets/Scripts/LevelEditor/Selector.cs

@@ -1,6 +1,7 @@
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
+using UnityEngine.EventSystems;
 
 namespace RhythmHeavenMania.Editor
 {
@@ -14,10 +15,5 @@ namespace RhythmHeavenMania.Editor
         {
             instance = this;
         }
-
-        private void Update()
-        {
-
-        }
     }
 }