[ACA-3899] Viewer thumbnails cannot be accessed by keyboard (#6150)

* accessibility

* add thumb focus

* close thumbs list event

* fix eventbus listener

* rename parameter

* track previous focused element

* implement FocusKeyManager

* fix getGlobalEventBus is deprecated

* keyboard navigation

* set tabindex

* setActiveItem on list change

* update  test

lib/core/viewer/components/pdf-viewer.component.html

@@ -3,7 +3,12 @@
         <div class="adf-pdf-viewer__thumbnails">
             <div class="adf-thumbnails-template__container">
                 <div class="adf-thumbnails-template__buttons">
-                    <button mat-icon-button data-automation-id='adf-thumbnails-close' (click)="toggleThumbnails()">
+                    <button
+                        mat-icon-button
+                        data-automation-id='adf-thumbnails-close'
+                        (click)="toggleThumbnails()"
+                        [attr.aria-label]="'ADF_VIEWER.ARIA.THUMBNAILS_PANLEL_CLOSE' | translate"
+                        title="{{ 'ADF_VIEWER.ACTIONS.CLOSE' | translate }}">
                         <mat-icon>close</mat-icon>
                     </button>
                 </div>
@@ -13,7 +18,7 @@
                 </ng-container>
 
                 <ng-container *ngIf="!thumbnailsTemplate">
-                    <adf-pdf-thumbnails [pdfViewer]="pdfViewer"></adf-pdf-thumbnails>
+                    <adf-pdf-thumbnails (close)="toggleThumbnails()" [pdfViewer]="pdfViewer"></adf-pdf-thumbnails>
                 </ng-container>
             </div>
         </div>