New Away Site: Hiskyn Treasure Trove (#21324)

EDIT: This is complete and no longer a work in progress. I've tried to
make sure that everything is tested and working properly but if there
are issues please let me know.

This away site is intended to be a high risk, high reward, encounter.
I'm also attempting to increase its replayability by incorporating a
number of sections and submaps that will be newly generated each time.

Things added or changed:
- Additional traps and environmental hazards.
- Lava is now more deadly. It used to only set you on fire, now it will
burn you appropriately.
- Minor sprite fixes for uncommon elements for easier mapping; throwers,
step triggers.
- Map and associated files, submap json, landmarks, areas, ect.

---------

Signed-off-by: Evandorf <ej_denton@msn.com>
Co-authored-by: Kano <89972582+kano-dot@users.noreply.github.com>

code/game/objects/random/random.dm

@@ -22,27 +22,19 @@
 
 	return INITIALIZE_HINT_QDEL
 
-// this function should return a specific item to spawn
-/obj/random/proc/item_to_spawn()
-	return 0
-
 /obj/random/proc/post_spawn(obj/thing)
 	LOG_DEBUG("random_obj: [DEBUG_REF(src)] registered itself as having post_spawn, but did not override post_spawn()!")
 
 // creates the random item
 /obj/random/proc/spawn_item()
-	if (spawnlist)
+	if(spawnlist)
 		var/itemtype = pick(spawnlist)
 		. = new itemtype(loc)
 
-	else if (problist)
+	if(problist)
 		var/itemtype = pickweight(problist)
 		. = new itemtype(loc)
 
-	else
-		var/itemtype = item_to_spawn()
-		. = new itemtype(loc)
-
 	if (!.)
 		LOG_DEBUG("random_obj: [DEBUG_REF(src)] returned null item!")
 
@@ -51,6 +43,3 @@
 	desc = "This item type is used to randomly spawn a given object at round-start"
 	icon_state = "x3"
 	var/spawn_object = null
-
-/obj/random/single/item_to_spawn()
-	return ispath(spawn_object) ? spawn_object : text2path(spawn_object)