Add vote statistics feature and improve vote page functionality

frontend/src/app/guards/auth.guard.ts

@@ -21,7 +21,7 @@ export class AuthGuard implements CanActivate {
     route: ActivatedRouteSnapshot,
     state: RouterStateSnapshot
   ): Observable<boolean | UrlTree> | Promise<boolean | UrlTree> | boolean | UrlTree {
-    if (!this.authService.checkAuthStatus()) {
+    if (!this.authService.isAuthenticated$()) {
       this.router.createUrlTree(['/']);
       const dialogRef = this.dialog.open(LoginDialogComponent, {
         width: '400px',