Add full-text search

Add a search box with a quick results popover, as well full results in
the sidebar on pressing enter.

app/services/map-ui.js

@@ -7,6 +7,7 @@ export default class MapUiService extends Service {
   @tracked isCreating = false;
   @tracked creationCoordinates = null;
   @tracked returnToSearch = false;
+  @tracked currentCenter = null;
 
   selectPlace(place) {
     this.selectedPlace = place;
@@ -38,4 +39,8 @@ export default class MapUiService extends Service {
   updateCreationCoordinates(lat, lon) {
     this.creationCoordinates = { lat, lon };
   }
+
+  updateCenter(lat, lon) {
+    this.currentCenter = { lat, lon };
+  }
 }