Copy ItemStack received in inventory slot element

Since the item stack is passed to the visualizer, it needs to be copied as the visualizer may modify it.

Author: NichtStudioCode

invui/src/main/java/xyz/xenondevs/invui/gui/SlotElement.java

@@ -162,7 +162,7 @@ public InventoryLink(Inventory inventory, int slot, Property<@Nullable ItemProvi
         @Override
         public @Nullable ItemStack getItemStack(Player player) {
             var locale = Languages.getInstance().getLocale(player);
-            var itemStack = inventory.getUnsafeItem(slot);
+            var itemStack = inventory.getItem(slot);
 
             // pass actual item stack to visualizer
             var visualization = visualizer.apply(itemStack);