Move heal locations data to their associated map.json (#2034)

data/maps/MossdeepCity/map.json

@@ -481,5 +481,12 @@
       "player_facing_dir": "BG_EVENT_PLAYER_FACING_ANY",
       "script": "MossdeepCity_EventScript_WhiteRock"
     }
+  ],
+  "heal_locations": [
+    {
+      "id": "HEAL_LOCATION_MOSSDEEP_CITY",
+      "x": 28,
+      "y": 17
+    }
   ]
 }