site search should not adopt existing URL query string parameters (#2818)

src/app/search-navbar: do not merge existing query params

Do not merge existing query params when using site search from MyDSpace workflow.

src/app/search-navbar/search-navbar.component.ts

@@ -66,8 +66,7 @@ export class SearchNavbarComponent {
     this.searchForm.reset();
 
     this.router.navigate(linkToNavigateTo, {
-      queryParams: queryParams,
-      queryParamsHandling: 'merge'
+      queryParams: queryParams
     });
   }
 }