feat(aio): improve search results functionality

* Ensure that all indexed documents are displayed in the search results.
(Previously the guide documents were not appearing because we only showed
results that had a `name` property, rather than a `name` or `title`.)
* Group the results by their containing folder (e.g. api, guide, tutorial, etc).
* Hide the results when the user hits the ESC key.
* Hide the results when the user clicks on a search result

Closes #14852

aio/src/testing/location.service.ts

@@ -3,6 +3,8 @@ import { BehaviorSubject } from 'rxjs/BehaviorSubject';
 export class MockLocationService {
   urlSubject = new BehaviorSubject<string>(this.initialUrl);
   currentUrl = this.urlSubject.asObservable();
+  search = jasmine.createSpy('search').and.returnValue({});
+  setSearch = jasmine.createSpy('setSearch');
   constructor(private initialUrl) {}
 }
 

aio/src/testing/search.service.ts

@@ -0,0 +1,10 @@
+import { Subject } from 'rxjs/Subject';
+import { SearchResults } from 'app/search/search.service';
+
+export class MockSearchService {
+  searchResults = new Subject<SearchResults>();
+  initWorker = jasmine.createSpy('initWorker');
+  loadIndex = jasmine.createSpy('loadIndex');
+  search = jasmine.createSpy('search');
+  hideResults = jasmine.createSpy('hideResults');
+}