always use thumbnail component for files not supported by the media viewer, and switch to themed version of thumbnail component

Author: artlowel

src/app/item-page/media-viewer/media-viewer.component.html

@@ -16,12 +16,7 @@
     </ng-container>
   </div>
   <ng-template #showThumbnail>
-    <ds-themed-media-viewer-image *ngIf="mediaOptions.image && mediaOptions.video"
-      [image]="(thumbnailsRD$ | async)?.payload?.page[0]?._links.content.href || thumbnailPlaceholder"
-      [preview]="false"
-    ></ds-themed-media-viewer-image>
-    <ds-thumbnail *ngIf="!(mediaOptions.image && mediaOptions.video)"
-                  [thumbnail]="(thumbnailsRD$ | async)?.payload?.page[0]">
-    </ds-thumbnail>
+    <ds-themed-thumbnail [thumbnail]="(thumbnailsRD$ | async)?.payload?.page[0]">
+    </ds-themed-thumbnail>
   </ng-template>
 </ng-container>

src/app/item-page/media-viewer/media-viewer.component.spec.ts

@@ -139,9 +139,9 @@ describe('MediaViewerComponent', () => {
       expect(mediaItem.thumbnail).toBe(null);
     });
 
-    it('should display a default, thumbnail', () => {
+    it('should display a default thumbnail', () => {
       const defaultThumbnail = fixture.debugElement.query(
-        By.css('ds-themed-media-viewer-image')
+        By.css('ds-themed-thumbnail')
       );
       expect(defaultThumbnail.nativeElement).toBeDefined();
     });