[DNM][DNM][WIP] Projectile backend code port and update

Ports#54924,  #65061, #59804 from /tg.
adds auxiliary code from /tg to make code work.

code/modules/ruins/objects_and_mobs/necropolis_gate.dm

@@ -59,10 +59,10 @@
 /obj/structure/necropolis_gate/singularity_pull()
 	return 0
 
-/obj/structure/necropolis_gate/CanPass(atom/movable/mover, turf/target)
-	if(get_dir(loc, target) == dir)
-		return !density
-	return 1
+/obj/structure/necropolis_gate/CanAllowThrough(atom/movable/mover, turf/target)
+	. = ..()
+	if(!(get_dir(loc, target) == dir))
+		return TRUE
 
 /obj/structure/necropolis_gate/CheckExit(atom/movable/O, target)
 	if(get_dir(O.loc, target) == dir)

code/modules/ruins/objects_and_mobs/sin_ruins.dm

@@ -80,7 +80,8 @@
 	icon = 'icons/mob/blob.dmi'
 	color = rgb(145, 150, 0)
 
-/obj/effect/gluttony/CanPass(atom/movable/mover, turf/target)//So bullets will fly over and stuff.
+/obj/effect/gluttony/CanAllowThrough(atom/movable/mover, turf/target)//So bullets will fly over and stuff.
+	. = ..()
 	if(ishuman(mover))
 		var/mob/living/carbon/human/H = mover
 		if(H.nutrition >= NUTRITION_LEVEL_FAT)
@@ -90,8 +91,6 @@
 			to_chat(H, "<span class='warning'>You're repulsed by even looking at [src]. Only a pig could force themselves to go through it.</span>")
 	if(istype(mover, /mob/living/simple_animal/hostile/morph))
 		return TRUE
-	else
-		return FALSE
 
 /obj/structure/mirror/magic/pride //Pride's mirror: Used in the Pride ruin.
 	name = "pride's mirror"