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/language/outsider.dm

@@ -1,35 +1,3 @@
-/datum/language/xenocommon
-	name = LANGUAGE_XENOMORPH
-	colour = "alien"
-	desc = "The common tongue of the xenomorphs."
-	speech_verb = "hisses"
-	ask_verb = "hisses"
-	exclaim_verb = "hisses"
-	key = "z"
-	flags = RESTRICTED
-	syllables = list("sss","sSs","SSS")
-	machine_understands = FALSE
-
-/datum/language/xenos
-	name = LANGUAGE_HIVEMIND
-	desc = "Xenomorphs have the strange ability to commune over a psychic hivemind."
-	speech_verb = "hisses"
-	ask_verb = "hisses"
-	exclaim_verb = "hisses"
-	colour = "alien"
-	key = "a"
-	flags = RESTRICTED | HIVEMIND
-
-/datum/language/xenos/check_special_condition(var/mob/other)
-
-	var/mob/living/carbon/M = other
-	if(!istype(M))
-		return 1
-	if(locate(/obj/item/organ/xenos/hivenode) in M.internal_organs)
-		return 1
-
-	return 0
-
 /datum/language/ling
 	name = LANGUAGE_CHANGELING
 	desc = "Although they are normally wary and suspicious of each other, changelings can commune over a distance."