Medical/improvised gauze icons (#81802)

## About The Pull Request

Adds icons for stacks of medical gauze and improvised gauze, so that
they can be differentiated from stacks of cloth. Currently all 3 look
the same. Medical gauze is blue tinted like the medical tape, improvised
gauze is grey and a smaller size than medical gauze. Both have
attachment clips at the edge of the roll.


![image](https://github.com/tgstation/tgstation/assets/83487515/47bcd42e-7270-498e-aacb-15d5a39fd432)

## Why It's Good For The Game

Easier to tell three different items apart at a glance.

## Changelog

🆑 LT3
image: medical and improvised gauze are visibly different from cloth
/🆑

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

@@ -310,6 +310,7 @@
 	name = "improvised gauze"
 	singular_name = "improvised gauze"
 	desc = "A roll of cloth roughly cut from something that does a decent job of stabilizing wounds, but less efficiently so than real medical gauze."
+	icon_state = "gauze_imp"
 	self_delay = 6 SECONDS
 	other_delay = 3 SECONDS
 	splint_factor = 0.85