Rework Lavaland tunnel themes. (#26599)

* Rework Lavaland tunnel themes.

* Fix deeprock mob density; ensure 1 vetus/bubblegum

* goddamnit

* bring spawn odds closer in line to head, fix tendril collapse range

* Move define to global dir

* don't need initial here

* define magic number properly

* make type of var clear

* CHECK_TICK during procgen

* less tendril cities, no tendrils in oasis centers

* revert no_lava helpers for now

* add NO_LAVA_GEN flag check back to safe_replace

* add blackbox feedback for themes

_maps/map_files/RandomRuins/LavaRuins/lavaland_surface_althland_facility.dmm

@@ -115,6 +115,10 @@
 /obj/effect/decal/cleanable/dirt,
 /turf/simulated/floor/plating/lavaland_air,
 /area/ruin/unpowered/althland_processing)
+"cM" = (
+/obj/effect/mapping_helpers/no_lava,
+/turf/template_noop,
+/area/lavaland/surface/outdoors/unexplored)
 "dh" = (
 /obj/effect/mapping_helpers/no_lava,
 /obj/structure/disposalpipe/segment/corner{
@@ -646,6 +650,9 @@
 /obj/machinery/economy/vending/chinese,
 /turf/simulated/floor/plating/lavaland_air,
 /area/ruin/unpowered/althland_processing)
+"yh" = (
+/turf/template_noop,
+/area/lavaland/surface/outdoors/unexplored)
 "zd" = (
 /obj/effect/decal/cleanable/dirt,
 /obj/effect/decal/cleanable/dirt,
@@ -1443,26 +1450,26 @@ bV
 bV
 bV
 bV
-bV
-bV
-bV
-bV
-bV
-bV
-bV
-bV
-bV
-bV
-bV
-bV
-bV
-bV
-bV
-bV
-bV
-bL
-bL
-bL
+yh
+yh
+yh
+yh
+yh
+yh
+yh
+yh
+yh
+yh
+yh
+yh
+yh
+yh
+yh
+yh
+yh
+yh
+yh
+yh
 bL
 bL
 bL
@@ -1479,19 +1486,19 @@ bV
 bV
 ab
 ab
-bV
-bV
-bV
-bV
-ab
-bV
-bV
-bV
-bV
-bV
-ab
-ab
+yh
+yh
+yh
+yh
 ab
+yh
+yh
+yh
+yh
+yh
+yh
+yh
+yh
 ab
 GF
 ab
@@ -1524,7 +1531,7 @@ ab
 ab
 bT
 ab
-ab
+cb
 ab
 ab
 ab
@@ -2712,9 +2719,9 @@ ab
 ab
 ab
 ab
-ab
-ab
-ab
+cM
+cM
+cM
 ab
 ab
 bL
@@ -2748,9 +2755,9 @@ bV
 bV
 bV
 bV
-ab
-ab
-ab
+cM
+cM
+cM
 bV
 bV
 bV