Copy-Paste Port of /tg/station's Shadowlings

Ports tgstation/-tg-station#8157

This won't compile, needs to be bugfixed and tested. The only reason I
am PRing  this right now is so that we don't have multiple people
working on the same thing.

@ZomgPonies This will require PROBABILITY SHADOWLING # to be added to
game_options.txt, and will likely require SQL database additions for the
BE_SHADOWLING antag preference.

code/modules/mob/living/simple_animal/ascendant_shadowling.dm

@@ -0,0 +1,33 @@
+/mob/living/simple_animal/ascendant_shadowling
+	name = "Ascendant Shadowling"
+	desc = "A large, floating eldritch horror. It has pulsing markings all about its body and large horns. It seems to be floating without any form of support."
+	icon = 'icons/mob/mob.dmi'
+	icon_state = "shadowling_ascended"
+	icon_living = "shadowling_ascended"
+	speak_emote = list("telepathically thunders", "telepathically booms")
+	force_threshold = INFINITY //Can't die by normal means
+	health = 100000
+	maxHealth = 100000
+	speed = 0
+	var/phasing = 0
+	see_in_dark = 8
+	see_invisible = SEE_INVISIBLE_MINIMUM
+
+	response_help   = "stares at"
+	response_disarm = "flails at"
+	response_harm   = "flails at"
+
+	harm_intent_damage = 0
+	melee_damage_lower = 35
+	melee_damage_upper = 35
+	attacktext = "claws at"
+	attack_sound = 'sound/weapons/slash.ogg'
+
+	minbodytemp = 0
+	maxbodytemp = INFINITY
+	environment_smash = 2
+
+	faction = list("faithless")
+
+/mob/living/simple_animal/ascendant_shadowling/Process_Spacemove(var/movement_dir = 0)
+	return 1 //copypasta from carp code