Gives constable helmet a hair mask and its armor back, fixes some hair masks not working (#92465)

## About The Pull Request

Also, all middle hair masks were broken because they had an incorrectly
set icon_state
Closes #92450

## Why It's Good For The Game

Its supposed to be a replacement for the security helmet, and while it
makes sense that it doesn't act as a full helmet (as it doesn't fully
cover your head), it still probably should have armor as per original
design (and also to not be useless for sec, who are the intended users
of this item)

## Changelog
🆑
fix: Fixed constable helmet not having any armor
fix: Fixed some hair masks not working
/🆑

code/datums/sprite_accessories.dm

@@ -64,7 +64,7 @@
 	var/strict_coverage_zones = NONE
 
 /datum/hair_mask/standard_hat_middle
-	icon_state = "hide_above_45deg_medium"
+	icon_state = "hide_above_45deg"
 	strict_coverage_zones = HAIR_APPENDAGE_TOP
 
 /datum/hair_mask/standard_hat_low

code/modules/clothing/head/hat.dm

@@ -27,6 +27,8 @@
 	inhand_icon_state = null
 	custom_price = PAYCHECK_COMMAND * 1.5
 	worn_y_offset = 4
+	armor_type = /datum/armor/head_helmet
+	hair_mask = /datum/hair_mask/standard_hat_middle
 
 /obj/item/clothing/head/costume/spacepolice
 	name = "space police cap"