Dynamic Human Icon Generation For Simple/Basic Mobs (& Cardboard Cutouts) (#72517)

## About The Pull Request
revive of #68760
this time a proc, not an element
this time supports cardboard cutouts
this time supports mob corpses

![image](https://user-images.githubusercontent.com/23585223/211064291-81070650-189f-4afa-8116-81b687e3ea35.png)

## Why It's Good For The Game
prevents these icons ever being outdated, they'll always look what they
are supposed to, saves spriting work

## Changelog
🆑 Fikou, a hood by Viro
refactor: humanoid mobs and cardboard cutouts automatically generate
their sprites, they no longer will be outdated
/🆑

Co-authored-by: Time-Green <timkoster1@hotmail.com>

code/modules/mob_spawn/mob_spawn.dm

@@ -207,8 +207,10 @@
 	///burn damage this corpse will spawn with
 	var/burn_damage = 0
 
-/obj/effect/mob_spawn/corpse/Initialize(mapload)
+/obj/effect/mob_spawn/corpse/Initialize(mapload, no_spawn)
 	. = ..()
+	if(no_spawn)
+		return
 	switch(spawn_when)
 		if(CORPSE_INSTANT)
 			INVOKE_ASYNC(src, PROC_REF(create))