fix(search): geocode through the server, not the browser

- Google's Geocoding web service refuses referrer-restricted keys, so the
  browser call forced GOOGLE_MAPS_API_KEY to ship unrestricted
- add /api/google/geocode and /api/google/reverse-geocode, using the server
  key like Places and Street View already do
- the browser key now needs the Map Tiles API only

server/providers/places.js

@@ -1,8 +1,13 @@
 /** Place-search and route middleware for Node development servers. */
-export { googlePlacesContextProxy } from './places/google.js';
+export {
+  googlePlacesContextProxy,
+  validateGeocodeAddress,
+  geocodeBounds,
+} from './places/google.js';
 export {
   googleServerApiKey,
   keylessGooglePlacesResponse,
+  keylessGoogleGeocodeResponse,
 } from './places/google-key.js';
 export { installRouteMiddleware } from './places/routes.js';
 export {