feat(aio): first pass API docs redesign (#21874)

Includes:

* display ToC for API docs
* update dgeni-packages to 0.24.1
* add floating sidebar in API docs
* add breadcrumbs and structured data for Google crawler
* improved rendering of method overloads
* properties rendered in a table
* params rendered with docs
* removal of outdated "infobox" from all API docs

PR Close #21874

aio/tools/transforms/angular-api-package/processors/computeApiBreadCrumbs.spec.js

@@ -0,0 +1,39 @@
+const testPackage = require('../../helpers/test-package');
+const processorFactory = require('./computeApiBreadCrumbs');
+const Dgeni = require('dgeni');
+
+describe('angular-api-package: computeApiBreadCrumbs processor', () => {
+
+  it('should be available on the injector', () => {
+    const dgeni = new Dgeni([testPackage('angular-api-package')]);
+    const injector = dgeni.configureInjector();
+    const processor = injector.get('computeApiBreadCrumbs');
+    expect(processor.$process).toBeDefined();
+    expect(processor.$runAfter).toEqual(['paths-computed']);
+    expect(processor.$runBefore).toEqual(['rendering-docs']);
+  });
+
+  it('should attach a breadCrumbs property to each of the EXPORT_DOC_TYPES docs', () => {
+    const EXPORT_DOC_TYPES = ['class', 'interface'];
+    const processor = processorFactory(EXPORT_DOC_TYPES);
+
+    const docs = [
+      { docType: 'class', name: 'ClassA', path: 'module-1/class-a', moduleDoc: { id: 'moduleOne', path: 'module-1' } },
+      { docType: 'interface', name: 'InterfaceB', path: 'module-2/interface-b', moduleDoc: { id: 'moduleTwo', path: 'module-2' } },
+      { docType: 'guide', name: 'Guide One', path: 'guide/guide-1' },
+    ];
+    processor.$process(docs);
+
+    expect(docs[0].breadCrumbs).toEqual([
+      { text: 'API', path: '/api' },
+      { text: '@angular/moduleOne', path: 'module-1' },
+      { text: 'ClassA', path: 'module-1/class-a' },
+    ]);
+    expect(docs[1].breadCrumbs).toEqual([
+      { text: 'API', path: '/api' },
+      { text: '@angular/moduleTwo', path: 'module-2' },
+      { text: 'InterfaceB', path: 'module-2/interface-b' },
+    ]);
+    expect(docs[2].breadCrumbs).toBeUndefined();
+  });
+});