On demand belly loading & multibelly (#16758)

* Moves simple mob belly loading to on demans

* style

* early

* multibelly

* even more human

* .

* bunch of update_fullness

* animals need an icon refresh

* the icon has the fullness part, optimize that

* one more

code/game/objects/structures/ghost_pods/event_vr.dm

@@ -105,6 +105,8 @@
 	var/mob/living/simple_mob/newPred = new mobtype(get_turf(src))
 	qdel(newPred.ai_holder)
 	newPred.ai_holder = null
+	newPred.voremob_loaded = TRUE // On-demand belly loading.
+	newPred.init_vore() // On-demand belly loading.
 	//newPred.movement_cooldown = 0			// The "needless artificial speed cap" exists for a reason
 	if(M.mind)
 		M.mind.transfer_to(newPred)
@@ -142,6 +144,8 @@
 		return
 
 	var/mob/living/simple_mob/vore/morph/newMorph = new /mob/living/simple_mob/vore/morph(get_turf(src))
+	newMorph.voremob_loaded = TRUE // On-demand belly loading.
+	newMorph.init_vore() // On-demand belly loading.
 	if(M.mind)
 		M.mind.transfer_to(newMorph)
 	to_chat(M, span_notice("You are a " + span_bold("Morph") + ", somehow having gotten aboard the station in your wandering. \