migrate all /obj/item from /New() to /Initialize() (#31232)

* migrate all /obj/item from /New() to /Initialize()

* move GLOB.chemical_reagents_list creation to /world/New()

* review

* oops

* autodoc a smart var

code/game/objects/structures/stool_bed_chair_nest/bed.dm

@@ -263,9 +263,12 @@
 	var/obj/item/roller/held
 	var/obj/carry_holo = FALSE
 
-/obj/item/roller_holder/New()
-	..()
-	held = new /obj/item/roller(src)
+/obj/item/roller_holder/Initialize(mapload)
+	. = ..()
+	create_roller()
+
+/obj/item/roller_holder/proc/create_roller()
+	held = new(src)
 
 /obj/item/roller_holder/interact_with_atom(atom/target, mob/living/user, list/modifiers)
 	if(!istype(target, /obj/item/roller))
@@ -306,8 +309,7 @@
 	icon_state = "holo_retracted"
 	carry_holo = TRUE
 
-/obj/item/roller_holder/holo/New()
-	..()
+/obj/item/roller_holder/holo/create_roller()
 	held = new /obj/item/roller/holo(src)
 
 /*

code/game/objects/structures/watercloset.dm

@@ -720,8 +720,8 @@ MAPPING_DIRECTIONAL_HELPERS_CUSTOM(/obj/structure/sink/kitchen/old, 18, -4, 0, 0
 	result = /obj/structure/sink
 	result_name = "sink"
 
-/obj/item/bathroom_parts/New()
-	..()
+/obj/item/bathroom_parts/Initialize(mapload)
+	. = ..()
 	desc = "An entire [result_name] in a box, straight from Space Sweden. It has an [pick("unpronounceable", "overly accented", "entirely gibberish", "oddly normal-sounding")] name."
 
 /obj/item/bathroom_parts/activate_self(mob/user)