Hotbar Improvements + Item Action Integration Test (#2749)

* my IDE keeps wanting to change this so....

* Add item actions integration test, fix bug where empty item action
dict was left in SharedActionsComponent state

* bigger hotbar arrows

* nice wide hotbar pagination hitboxes

* add ability to switch hotbar loadout
via keybinds

* always highlight on drag over
of actions hotbar

* dont rely on content entity for integration test

Content.Shared/GameObjects/Components/Mobs/SharedActionsComponent.cs

@@ -265,6 +265,10 @@ namespace Content.Shared.GameObjects.Components.Mobs
                 return;
 
             itemStates.Remove(actionType);
+            if (itemStates.Count == 0)
+            {
+                _itemActions.Remove(item);
+            }
             AfterActionChanged();
             Dirty();
         }