sword sheathes can now be worn on all suits (#94816)

## About The Pull Request

This PR makes it so you can wear sheathes on all suit storages

## Why It's Good For The Game
It mostly allows players freedom to shuffle stuff around they already
have to haggle a sheathe around with the sword in it while still having
most of their storage thing vs a gun, which allows players freedom when
it comes to setups, but also make them be able to use counterattack
mechanic. heres some cosmetic setups i just made up that isn't reliant
on armour

in the future we can make things less reliant on backpacks when it comes
to storage

<img width="227" height="317" alt="image"
src="https://github.com/user-attachments/assets/83a684cb-a096-4a92-af8f-ebc8d982a463"
/>

## Changelog
🆑 Ezel
balance: sabre, parsnip, gladius sheathe can now be worn on suit
storages
fix: mirrors gladius belt worn sprite so it doesn't overlap with belted
revolvers
image: adds mirrored belt sprites
/🆑

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

@@ -595,7 +595,7 @@
 
 /obj/item/storage/belt/sheath/Initialize(mapload)
 	. = ..()
-	AddElement(/datum/element/update_icon_updates_onmob)
+	AddElement(/datum/element/update_icon_updates_onmob, action_slots)
 	RegisterSignal(src, COMSIG_ATOM_STORED_ITEM, PROC_REF(post_resheath))
 
 /obj/item/storage/belt/sheath/Destroy(force)
@@ -736,6 +736,7 @@
 	icon_state = "sheath"
 	inhand_icon_state = "sheath"
 	worn_icon_state = "sheath"
+	action_slots = ITEM_SLOT_BELT | ITEM_SLOT_SUITSTORE
 	storage_type = /datum/storage/sabre_belt
 	stored_blade = /obj/item/melee/sabre
 
@@ -745,6 +746,7 @@
 	icon_state = "grass_sheath"
 	inhand_icon_state = "grass_sheath"
 	worn_icon_state = "grass_sheath"
+	action_slots = ITEM_SLOT_BELT | ITEM_SLOT_SUITSTORE
 	storage_type = /datum/storage/green_sabre_belt
 
 /obj/item/storage/belt/sheath/gladius
@@ -753,6 +755,7 @@
 	icon_state = "gladius_sheath"
 	inhand_icon_state = "gladius_sheath"
 	worn_icon_state = "gladius_sheath"
+	action_slots = ITEM_SLOT_BELT | ITEM_SLOT_SUITSTORE
 	storage_type = /datum/storage/gladius_belt
 	stored_blade = /obj/item/claymore/gladius