Added thumbnail property to browse entry model.

src/app/core/shared/browse-entry.model.ts

@@ -40,6 +40,12 @@ export class BrowseEntry extends ListableObject implements TypedObject {
   @autoserializeAs('valueLang')
   language: string;
 
+  /**
+   * Thumbnail link used when browsing items with showThumbs config enabled.
+   */
+  @autoserializeAs('thumbnail')
+  thumbnail: string;
+
   /**
    * The count of this browse entry
    */