Craftable material sniffers (#74798)

## About The Pull Request

Are YOU annoyed about never finding the fucking mats you need? Slap some
cable coil on an analyzer and find that untouched sheet of iron and or
glass. It's a pinpointer for basic sheets.

## Why It's Good For The Game

Originally I meant to give this as something borgs might want, but I
realized they really won't have a great time using it and the situation
is more about botanists not being asked, and not knowing how to grow
lots of iron, repeat for all other departments. Awareness problems!!!

But I still like the item as a miscellaneous craftable.

## Changelog
🆑
add: Craftable Material sniffers
/🆑

---------

Co-authored-by: Fikou <23585223+Fikou@users.noreply.github.com>

code/game/objects/items/stacks/sheets/glass.dm

@@ -32,6 +32,7 @@ GLOBAL_LIST_INIT(glass_recipes, list ( \
 	matter_amount = 4
 	cost = 500
 	source = /datum/robot_energy_storage/glass
+	sniffable = TRUE
 
 /datum/armor/sheet_glass
 	fire = 50

code/game/objects/items/stacks/sheets/sheet_types.dm

@@ -152,6 +152,7 @@ GLOBAL_LIST_INIT(metal_recipes, list ( \
 	cost = 500
 	source = /datum/robot_energy_storage/iron
 	stairs_type = /obj/structure/stairs
+	sniffable = TRUE
 
 /obj/item/stack/sheet/iron/Initialize(mapload)
 	. = ..()

code/game/objects/items/stacks/sheets/sheets.dm

@@ -17,11 +17,27 @@
 	var/point_value = 0 //turn-in value for the gulag stacker - loosely relative to its rarity.
 	///What type of wall does this sheet spawn
 	var/walltype
+	/// whether this sheet can be sniffed by the material sniffer
+	var/sniffable = FALSE
 
 /obj/item/stack/sheet/Initialize(mapload, new_amount, merge = TRUE, list/mat_override=null, mat_amt=1)
 	. = ..()
 	pixel_x = rand(-4, 4)
 	pixel_y = rand(-4, 4)
+	if(sniffable && is_station_level(z) && amount < 10)
+		GLOB.sniffable_sheets += src
+
+/obj/item/stack/sheet/Destroy(force)
+	if(sniffable)
+		GLOB.sniffable_sheets -= src
+	return ..()
+
+/obj/item/stack/sheet/add(_amount)
+	. = ..()
+	if(sniffable && is_station_level(z) && amount > 10)
+		GLOB.sniffable_sheets += src
+
+/// removing from sniffable handled by the sniffer itself when it checks for targets
 
 /**
  * Facilitates sheets being smacked on the floor