feat(docs-infra): enable filtering by package on API list page (#24631)

PR Close #24631

aio/src/app/custom-elements/api/api-list.component.html

@@ -21,10 +21,10 @@
 
 <article class="api-list-container l-content-small docs-content">
   <div *ngFor="let section of filteredSections | async" >
-    <h2><a [href]="section.path">{{section.title}}</a></h2>
-    <ul class="api-list">
+    <h2 *ngIf="section.items"><a [href]="section.path">{{section.title}}</a></h2>
+    <ul class="api-list" *ngIf="section.items?.length">
       <ng-container *ngFor="let item of section.items">
-        <li *ngIf="item.show" class="api-item">
+        <li class="api-item">
           <a [href]="item.path"><span class="symbol {{item.docType}}"></span> {{item.title}}</a>
         </li>
       </ng-container>