Stack items have a number indicating stack size in inventory (#94705)

## About The Pull Request

<img width="528" height="200" alt="image"
src="https://github.com/user-attachments/assets/41a30b57-2799-44c8-82cd-ce2f8c8c22c4"
/>

Number only shows up when it's in the inventory or held - in world it
looks as-normal

(I'm pretty sure this idea was subconsciously inspired by another
server, but I don't remember...)

## Why It's Good For The Game

Makes it easier to use stacks that don't have a visual sprite change -
IE you no longer have to spam examine to see how many you have left

## Changelog

🆑 Melbert
qol: Stack items have a number indicating stack size while held or in
inventory.
/🆑

code/datums/storage/storage_interface.dm

@@ -113,7 +113,8 @@
 	for(var/obj/item as anything in storage_contents)
 		item.mouse_opacity = MOUSE_OPACITY_OPAQUE
 		item.screen_loc = "[current_x]:[screen_pixel_x],[current_y]:[screen_pixel_y]"
-		item.maptext = storage_contents[item]
+		if(parent_storage.numerical_stacking)
+			item.maptext = storage_contents[item]
 		SET_PLANE(item, ABOVE_HUD_PLANE, our_turf)
 		current_x++
 		if(current_x - screen_start_x < columns)