build(aio): add API static members to search index (#21988)

Previously searching for `compose` did not include `Validators`
in the search results because we were not including all the
`static` members of API docs in the index.

PR Close #21988

aio/e2e/search.e2e-spec.ts

@@ -0,0 +1,28 @@
+import { SitePage } from './app.po';
+
+describe('site search', () => {
+  let page;
+
+  beforeEach(() => {
+    page = new SitePage();
+    page.navigateTo('');
+  });
+
+  it('should find pages when searching by a partial word in the title', () => {
+    page.enterSearch('ngCont');
+    expect(page.getSearchResults()).toContain('NgControl');
+
+    page.enterSearch('accessor');
+    expect(page.getSearchResults()).toContain('ControlValueAccessor');
+  });
+
+  it('should find API docs whose instance member name matches the search query', () => {
+    page.enterSearch('decode');
+    expect(page.getSearchResults()).toContain('HttpParameterCodec');
+  });
+
+  it('should find API docs whose static method name matches the search query', () => {
+    page.enterSearch('compose');
+    expect(page.getSearchResults()).toContain('Validators');
+  });
+});