Add reservation code download feature

Introduces a download button in the reservation success component to allow users to download their reservation code as a text file. Adds utility methods in PdfService for downloading text and JSON files, and integrates the new download functionality into the component.

src/app/pdf.service.ts

@@ -7,7 +7,6 @@ import { Eintrittskarte } from '@infinimotion/model-frontend';
   providedIn: 'root',
 })
 export class PdfService {
-
   private ticketsGreatedSignal = signal(0);
   private totalTicketsSignal = signal(0);
 
@@ -108,4 +107,35 @@ export class PdfService {
 
     return `Ticket_${orderCode}_${timestamp}.pdf`;
   }
+
+  downloadTextFile(content: string, filename: string = 'textdatei.txt'): void {
+
+    const blob = new Blob([content], { type: 'text/plain;charset=utf-8' });
+    const url = window.URL.createObjectURL(blob);
+
+    const link = document.createElement('a');
+    link.href = url;
+    link.download = filename;
+
+    document.body.appendChild(link);
+    link.click();
+    document.body.removeChild(link);
+
+    window.URL.revokeObjectURL(url);
+  }
+
+  downloadJsonFile(data: any, filename: string = 'data.json'): void {
+    const content = JSON.stringify(data, null, 2);
+    const blob = new Blob([content], { type: 'application/json' });
+    const url = window.URL.createObjectURL(blob);
+
+    const link = document.createElement('a');
+    link.href = url;
+    link.download = filename;
+    document.body.appendChild(link);
+    link.click();
+    document.body.removeChild(link);
+    window.URL.revokeObjectURL(url);
+  }
 }
+