Split Open Map Overlays into Sea Marks and Ski Pistes layers

Each overlay is now its own Infrastructure row instead of a chip on one
shared row: sea-marks (token 6) and ski-pistes (token 7), both
enabled-only, built by createOsmOverlayLayers() from one descriptor
list. Drops the option group and its share-codec defaults, gives each
layer its own name, voice entry and CURRENT-STATE row, and shifts the
token-ledger fixtures to the next free digit 8.

src/i18n/locales/es.json

@@ -3010,6 +3010,5 @@
   "Left panels": "Paneles izquierdos",
   "Right panels": "Paneles derechos",
   "Sea Marks": "Señales marítimas",
-  "Ski Pistes": "Pistas de esquí",
-  "Open Map Overlays": "Capas de mapas abiertos"
+  "Ski Pistes": "Pistas de esquí"
 }