Add login capability; Add register page to routing; Block access from users that are not logged in.

webservice/Frontend/Aktienbot/src/app/Services/data.service.ts

@@ -5,7 +5,7 @@ const API_URL = 'http://localhost:8080/api/test/';
 @Injectable({
   providedIn: 'root',
 })
-export class UserService {
+export class DataService {
   constructor(private http: HttpClient) {}
   // getPublicContent(): Observable<any> {
   //   return this.http.get(API_URL + 'all', { responseType: 'text' });