Reduce browse definition requests on simple item page (#3701)

* 121561 Reduce the number of browse definition requests on Item pages by reusing the navbar request for all browse indexes

* Fix test issues.

---------

Co-authored-by: Koen Pauwels <koen.pauwels@atmire.com>

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

@@ -1,4 +1,7 @@
-import { autoserialize } from 'cerialize';
+import {
+  autoserialize,
+  autoserializeAs,
+} from 'cerialize';
 
 import { BrowseByDataType } from '../../browse-by/browse-by-switcher/browse-by-data-type';
 import { CacheableObject } from '../cache/cacheable-object.model';
@@ -11,6 +14,9 @@ export abstract class BrowseDefinition extends CacheableObject {
   @autoserialize
   id: string;
 
+  @autoserializeAs('metadata')
+  metadataKeys: string[];
+
   /**
    * Get the render type of the BrowseDefinition model
    */