Generate heal location constants automatically, move data back to a single file.

data/maps/PewterCity/map.json

@@ -295,14 +295,5 @@
       "quantity": 1,
       "underfoot": false
     }
-  ],
-  "heal_locations": [
-    {
-      "id": "HEAL_LOCATION_PEWTER_CITY",
-      "x": 17,
-      "y": 26,
-      "respawn_map": "MAP_PEWTER_CITY_POKEMON_CENTER_1F",
-      "respawn_npc": "LOCALID_PEWTER_NURSE"
-    }
   ]
 }