GAGS-ifies the Hawaiian Shirt, adds it to the ClothesMate (#75866)

## About The Pull Request
Technically a port of
https://github.com/Skyrat-SS13/Skyrat-tg/pull/17085
On the tin, it was mentioned that they could use it, I had these
on-hand. Probably should have been up here in the first place anyways.

![dreamseeker_ktdTANkHU9](https://github.com/tgstation/tgstation/assets/76465278/1c067db1-7e5a-4a8e-b912-9df0182a39ea)

![dreamseeker_0jPbNpXygu](https://github.com/tgstation/tgstation/assets/76465278/d9d27197-5971-44d2-bcff-24eeb23e4a9a)

![dreamseeker_AVZClDGGRt](https://github.com/tgstation/tgstation/assets/76465278/6736429b-3ef2-499f-b147-342254f44b1d)

Also makes them available in the ClothesMate so that crew can enjoy this
beautiful... just... beautiful item.

Worth noting, this item may be reworked in the future to an accessory.
This is just the greyscale half, the hard part. Changing the type to an
accessory in the future is easy now.
## Why It's Good For The Game
GAGS is good for items like this that just deserve lots of color. And
making them available for crew to actually use is cool.
## Changelog
🆑
add: The Hawaiian Overshirt is now GAGS, and available to crew in the
ClothesMate. Mahalo a aloha!
/🆑

code/datums/greyscale/config_types/greyscale_configs.dm

@@ -928,6 +928,15 @@
 	icon_file = 'icons/mob/clothing/suits/costume.dmi'
 	json_config = 'code/datums/greyscale/json_configs/football_armor_worn.json'
 
+/datum/greyscale_config/hawaiian_shirt
+	name = "Hawaiian Overshirt"
+	icon_file = 'icons/obj/clothing/suits/costume.dmi'
+	json_config = 'code/datums/greyscale/json_configs/hawaiian_shirt.json'
+
+/datum/greyscale_config/hawaiian_shirt/worn
+	name = "Hawaiian Overshirt"
+	icon_file = 'icons/mob/clothing/suits/costume.dmi'
+
 /datum/greyscale_config/waistcoat
 	name = "Waistcoat"
 	icon_file = 'icons/obj/clothing/accessories.dmi'

code/datums/greyscale/json_configs/hawaiian_shirt.json

@@ -0,0 +1,16 @@
+{
+	"hawaiian_shirt": [
+		{
+			"type": "icon_state",
+			"icon_state": "hawaiianbase",
+			"blend_mode": "overlay",
+			"color_ids": [ 1 ]
+		},
+		{
+			"type": "icon_state",
+			"icon_state": "hawaiianflowers",
+			"blend_mode": "overlay",
+			"color_ids": [ 2 ]
+		}
+	]
+}

code/modules/clothing/suits/costume.dm

@@ -519,8 +519,12 @@
 /obj/item/clothing/suit/costume/hawaiian
 	name = "hawaiian overshirt"
 	desc = "A cool shirt for chilling on the beach."
-	icon_state = "hawaiian_blue"
+	icon_state = "hawaiian_shirt"
 	inhand_icon_state = null
+	greyscale_config = /datum/greyscale_config/hawaiian_shirt
+	greyscale_config_worn = /datum/greyscale_config/hawaiian_shirt/worn
+	greyscale_colors = "#313B82#CCCFF0"
+	flags_1 = IS_PLAYER_COLORABLE_1
 	species_exception = list(/datum/species/golem)
 
 /obj/item/clothing/suit/costume/football_armor

code/modules/vending/clothesmate.dm

@@ -98,6 +98,7 @@
 				/obj/item/clothing/suit/jacket/puffer = 2,
 				/obj/item/clothing/suit/jacket/letterman = 2,
 				/obj/item/clothing/suit/jacket/letterman_red = 2,
+				/obj/item/clothing/suit/costume/hawaiian = 4,
 				/obj/item/clothing/suit/costume/poncho = 1,
 				/obj/item/clothing/under/dress/skirt = 2,
 				/obj/item/clothing/under/suit/white/skirt = 2,