Revert "[MIRROR] Replace all secondary flags with bitflags stored in the flags_2 var" (#2457)

ok you know what yeah i think i'll properly mirror https://github.com/Citadel-Station-13/Citadel-Station-13/pull/2411

code/game/objects/items/stacks/sheets/leather.dm

@@ -179,7 +179,7 @@ GLOBAL_LIST_INIT(sinew_recipes, list ( \
 	singular_name = "hide plate"
 	max_amount = 6
 	novariants = FALSE
-	flags_1 = NOBLUDGEON_1
+	flags = NOBLUDGEON
 	w_class = WEIGHT_CLASS_NORMAL
 	layer = MOB_LAYER
 
@@ -192,7 +192,7 @@ GLOBAL_LIST_INIT(sinew_recipes, list ( \
 	singular_name = "drake plate"
 	max_amount = 10
 	novariants = FALSE
-	flags_1 = NOBLUDGEON_1
+	flags = NOBLUDGEON
 	w_class = WEIGHT_CLASS_NORMAL
 	layer = MOB_LAYER
 

code/game/objects/items/stacks/sheets/light.dm

@@ -9,7 +9,7 @@
 	throwforce = 5
 	throw_speed = 3
 	throw_range = 7
-	flags_1 = CONDUCT_1
+	flags = CONDUCT
 	max_amount = 60
 
 /obj/item/stack/light_w/attackby(obj/item/O, mob/user, params)

code/game/objects/items/stacks/sheets/sheet_types.dm

@@ -62,7 +62,7 @@ GLOBAL_LIST_INIT(metal_recipes, list ( \
 	icon_state = "sheet-metal"
 	materials = list(MAT_METAL=MINERAL_MATERIAL_AMOUNT)
 	throwforce = 10
-	flags_1 = CONDUCT_1
+	flags = CONDUCT
 	origin_tech = "materials=1"
 	resistance_flags = FIRE_PROOF
 	merge_type = /obj/item/stack/sheet/metal
@@ -109,7 +109,7 @@ GLOBAL_LIST_INIT(plasteel_recipes, list ( \
 	item_state = "sheet-metal"
 	materials = list(MAT_METAL=2000, MAT_PLASMA=2000)
 	throwforce = 10
-	flags_1 = CONDUCT_1
+	flags = CONDUCT
 	origin_tech = "materials=2"
 	armor = list(melee = 0, bullet = 0, laser = 0, energy = 0, bomb = 0, bio = 0, rad = 0, fire = 100, acid = 80)
 	resistance_flags = FIRE_PROOF