Adds USCM service jacket to SEA vendor (#4727)

# About the pull request

[Request from
Ethan](https://forum.cm-ss13.com/t/lack-of-mentors/4696/20)

Adds USCM service jacket to SEA Vendor as an armour option.

# Explain why it's good for the game

SEA can look pretty so they can feel pretty.


# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

Put screenshots and videos here with an empty line between the
screenshots and the `<details>` tags.

</details>


# Changelog
:cl:
add: USCM Service Jacket to SEA Vendor
/:cl:

code/game/machinery/vending/vendor_types/crew/sea.dm

@@ -56,6 +56,7 @@ GLOBAL_LIST_INIT(cm_vending_clothing_sea, list(
 		list("M3-L Pattern Light Armor", 0, /obj/item/clothing/suit/storage/marine/light, MARINE_CAN_BUY_ARMOR, VENDOR_ITEM_RECOMMENDED),
 		list("M3 Pattern Padded Armor", 0, /obj/item/clothing/suit/storage/marine/padded, MARINE_CAN_BUY_ARMOR, VENDOR_ITEM_REGULAR),
 		list("Bulletproof Vest", 0, /obj/item/clothing/suit/armor/bulletproof, MARINE_CAN_BUY_ARMOR, VENDOR_ITEM_REGULAR),
+		list("USCM Service Jacket", 0, /obj/item/clothing/suit/storage/jacket/marine/service, MARINE_CAN_BUY_ARMOR, VENDOR_ITEM_REGULAR),
 
 		list("ACCESSORIES (CHOOSE 1)", 0, null, null, null),
 		list("Brown Webbing Vest", 0, /obj/item/clothing/accessory/storage/black_vest/brown_vest, MARINE_CAN_BUY_ACCESSORY, VENDOR_ITEM_REGULAR),