improved coverage, type docs, removed startsWith option and general refactoring

src/app/shared/browse-by/browse-by.component.ts

@@ -17,6 +17,9 @@ import { ListableObject } from '../object-collection/shared/listable-object.mode
     fadeInOut
   ]
 })
+/**
+ * Component to display a browse-by page for any ListableObject
+ */
 export class BrowseByComponent {
   @Input() title: string;
   @Input() objects$: Observable<RemoteData<PaginatedList<ListableObject>>>;