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* removal of outdated "infobox" from all API docs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.js

@@ -0,0 +1,19 @@
+module.exports = function computeApiBreadCrumbs(EXPORT_DOC_TYPES) {
+  return {
+    $runAfter: ['paths-computed'],
+    $runBefore: ['rendering-docs'],
+    $process(docs) {
+      // Compute the breadcrumb for each doc by processing its containers
+      docs.forEach(doc => {
+        if (EXPORT_DOC_TYPES.indexOf(doc.docType) !== -1) {
+          doc.breadCrumbs = [
+            { text: 'API', path: '/api' },
+            { text: '@angular/' + doc.moduleDoc.id, path: doc.moduleDoc.path },
+            { text: doc.name, path: doc.path }
+          ];
+        }
+      });
+    }
+  };
+};
+