Fix: Items getting stuck after being placed in last inventory slots

-Items placed in last inventory slots won't get stuck anymore
-Bow item now can be dropped in equipment slots

Same Slot Items Fix

-You can no longer drop an item on top of another one
-Add Initialize for EquipmentSlot
-Add FakeInventory so that you can drag the items back into the inventory

Tutorial Part1 Version

This is the first version of the Drag&Drop system, coresponding to the Drag & Drop tutorial https://www.youtube.com/watch?v=h-2HwlGHfig&t=4s