added cors header for the nuxt server responses

server/api/getAllConfigItems.ts

@@ -1,7 +1,15 @@
 import { configItems, errorMsg } from "../middleware/configItems";
+import { OutgoingMessage } from 'http';
 
 export default defineEventHandler(async (event) => {
 
+    const headers: Record<string, Parameters<OutgoingMessage['setHeader']>[1]> = {
+        'Access-Control-Allow-Origin': 'https://tueitapp.tueit.de',
+        'Access-Control-Allow-Headers': 'authorization, content-type',
+        'Access-Control-Allow-Methods': 'GET,HEAD,PUT,PATCH,POST,DELETE',
+    };
+    setResponseHeaders(event, headers)
+
     if (!(errorMsg === '')) {
         throw createError({
             statusCode: 400,