Support stations with multiple z-levels (#35339)

* Remove ZLEVEL_STATION_PRIMARY

* Add Up and Down traits for use by ladders and chasms

* Give map_config creation its own proc

* Combine LoadConfig and ValidateJSON and remove transition_config

* Make space linkage a z-level trait

* Remove ZLEVEL_EMPTY_SPACE

* Update uses of GetFullMapPath

* Handle multi-Z stations and load Lavaland and Reebe at runtime

* Remove unused space maps

* Fix inappropriate z-expansion in map reader, improve logging

* Update comments relating to z-level configuration

* Add Lavaland and Reebe to ALL_MAPS

code/modules/events/pirates.dm

@@ -60,7 +60,7 @@
 	var/datum/map_template/pirate_event_ship/ship = new
 	var/x = rand(TRANSITIONEDGE,world.maxx - TRANSITIONEDGE - ship.width)
 	var/y = rand(TRANSITIONEDGE,world.maxy - TRANSITIONEDGE - ship.height)
-	var/z = ZLEVEL_EMPTY_SPACE
+	var/z = SSmapping.empty_space.z_value
 	var/turf/T = locate(x,y,z)
 	if(!T)
 		CRASH("Pirate event found no turf to load in")