Implementaiton of preview tab.

frontend/src/app/core/rest-services/publications/publication.rest-service.ts

@@ -26,4 +26,9 @@ export class PublicationRestService {
     params = params.set('query', searchCriteria);
     return lastValueFrom(this.httpClient.get<Publication[]>('/api/publications', { params }));
   }
+
+  preview(publicationText: string): Promise<string> {
+    const request = { text: publicationText };
+    return lastValueFrom(this.httpClient.post<string>('/api/publications/preview', request));
+  }
 }