Adds a welder chestrig! (#4029)

adds the welder chestrig to the game, spawning in the right hand of the
MT's, being in the marine surplus gear, the comtechs backpack selection,
the chestrig is a reskinned welder satchel but with more drip



# About the pull request

adds the welder chestrig to the game

means more drip for the mt's and comtechs/anyone with enthusiasm for
cades or raid fortified positions



more drip 

![Captura de pantalla
(335)](https://github.com/cmss13-devs/cmss13/assets/128561204/382f6d25-85b9-49ed-8a3e-0b516fc10915)
![Captura de pantalla
(336)](https://github.com/cmss13-devs/cmss13/assets/128561204/57ce4468-4783-4179-91d4-6ba2c7a06715)

# Changelog
:cl:
Adds a welder chestrig for MT's that works like a welder satchel, adds
the welder chestrig to the marine surplus vendor and comtech gear vendor
/:cl:

code/game/machinery/vending/vendor_types/squad_prep/squad_engineer.dm

@@ -110,6 +110,7 @@ GLOBAL_LIST_INIT(cm_vending_clothing_engi, list(
 		list("Technician Satchel", 0, /obj/item/storage/backpack/marine/satchel/tech, MARINE_CAN_BUY_BACKPACK, VENDOR_ITEM_REGULAR),
 		list("Technician Welderpack", 0, /obj/item/storage/backpack/marine/engineerpack, MARINE_CAN_BUY_BACKPACK, VENDOR_ITEM_MANDATORY),
 		list("Technician Welder-Satchel", 0, /obj/item/storage/backpack/marine/engineerpack/satchel, MARINE_CAN_BUY_BACKPACK, VENDOR_ITEM_REGULAR),
+		list("Technician Welder Chestrig", 0, /obj/item/storage/backpack/marine/engineerpack/welder_chestrig, MARINE_CAN_BUY_BACKPACK, VENDOR_ITEM_MANDATORY),
 
 		list("BELT (CHOOSE 1)", 0, null, null, null),
 		list("G8-A General Utility Pouch", 0, /obj/item/storage/backpack/general_belt, MARINE_CAN_BUY_BELT, VENDOR_ITEM_REGULAR),

code/game/machinery/vending/vendor_types/squad_prep/squad_prep.dm

@@ -77,6 +77,7 @@
 		list("Shotgun Scabbard", 5, /obj/item/storage/large_holster/m37, VENDOR_ITEM_REGULAR),
 		list("USCM Satchel", 10, /obj/item/storage/backpack/marine/satchel, VENDOR_ITEM_REGULAR),
 		list("USCM Technical Satchel", 10, /obj/item/storage/backpack/marine/satchel/tech, VENDOR_ITEM_REGULAR),
+		list("USCM Technical Chestrig", 10, /obj/item/storage/backpack/marine/engineerpack/welder_chestrig, VENDOR_ITEM_REGULAR),
 		list("USCM Uniform", 20, /obj/item/clothing/under/marine, VENDOR_ITEM_REGULAR),
 
 		list("BELTS", -1, null, null),

code/game/objects/items/storage/backpack.dm

@@ -914,6 +914,16 @@ GLOBAL_LIST_EMPTY_TYPED(radio_packs, /obj/item/storage/backpack/marine/satchel/r
 	max_fuel = 100
 	worn_accessible = TRUE
 
+/obj/item/storage/backpack/marine/engineerpack/welder_chestrig
+	name = "\improper Technician Welder Chestrig"
+	desc = "A specialized Chestrig worn by technicians and engineers. It carries one medium fuel tank for quick welder refueling and use."
+	icon_state = "welder_chestrig"
+	item_state = "welder_chestrig"
+	max_storage_space = 12
+	has_gamemode_skin = FALSE
+	max_fuel = 100
+	worn_accessible = TRUE
+
 // Pyrotechnician Spec backpack fuel tank
 /obj/item/storage/backpack/marine/engineerpack/flamethrower
 	name = "\improper USCM Pyrotechnician G6-2 fueltank"

code/modules/gear_presets/uscm_ship.dm

@@ -261,6 +261,7 @@
 	new_human.equip_to_slot_or_del(new /obj/item/storage/pouch/general/medium(new_human), WEAR_R_STORE)
 	new_human.equip_to_slot_or_del(new /obj/item/device/demo_scanner(new_human), WEAR_L_STORE)
 	new_human.equip_to_slot_or_del(new /obj/item/storage/bag/trash(new_human), WEAR_L_HAND)
+	new_human.equip_to_slot_or_del(new /obj/item/storage/backpack/marine/engineerpack/welder_chestrig, (new_human), WEAR_R_HAND)
 
 /datum/equipment_preset/uscm_ship/maint/load_rank(mob/living/carbon/human/new_human)
 	if(new_human.client)