Removes xenomorphs (#6686)

Xenomorphs are pretty much badly done and don't really fit at all. This pr fully removes the human type ones, alongside with the infection, eggs and facehuggers.

code/modules/mob/transform_procs.dm

@@ -201,25 +201,6 @@
 	return O
 
 //human -> alien
-/mob/living/carbon/human/proc/Alienize()
-	for(var/obj/item/W in src)
-		drop_from_inventory(W)
-	regenerate_icons()
-	canmove = 0
-	icon = null
-	invisibility = 101
-	for(var/t in organs)
-		qdel(t)
-
-	var/alien_caste = pick("Hunter","Sentinel","Drone")
-	var/mob/living/carbon/human/new_xeno = create_new_xenomorph(alien_caste,loc)
-
-	new_xeno.a_intent = I_HURT
-	new_xeno.key = key
-
-	to_chat(new_xeno, "<B>You are now an alien.</B>")
-	qdel(src)
-	return
 
 /mob/living/carbon/human/proc/slimeize(adult as num, reproduce as num)
 	if (transforming)