Renames a few variables. Also reorders icon fallback order again. (#51060)

* Renames a few variables. Also reorders fallback order again.
Renames item_state to inhand_icon_state
Renames mob_overlay_icon to worn_icon
Renames mob_overlay_state to worn_icon_state
worn_icon_state/mob_overlay_state now never gets used for inhands.

* Fixes some comments

* Fixes map issue

* Restart lints

* Properly resolves conflicts

code/game/objects/items/debug_items.dm

@@ -5,7 +5,7 @@
 	desc = "Spawn a human by aiming at a turf and clicking. Use in hand to change type."
 	icon = 'icons/obj/guns/magic.dmi'
 	icon_state = "nothingwand"
-	item_state = "wand"
+	inhand_icon_state = "wand"
 	lefthand_file = 'icons/mob/inhands/items_lefthand.dmi'
 	righthand_file = 'icons/mob/inhands/items_righthand.dmi'
 	w_class = WEIGHT_CLASS_SMALL
@@ -29,7 +29,7 @@
 	desc = "The original hypertool, born before them all. Use it in hand to unleash it's true power."
 	icon = 'icons/obj/device.dmi'
 	icon_state = "hypertool"
-	item_state = "hypertool"
+	inhand_icon_state = "hypertool"
 	toolspeed = 0.1
 	tool_behaviour = null