Enhance CSV import functionality with improved error messaging and logging

- Updated error message in CSVImportPanel to include a period for better readability.
- Added console logs in the CSV import API route to track the import process and precheck status.
- Removed redundant validation for 'Beguenstigter/Zahlungspflichtiger' to streamline error handling during CSV import.

client/src/components/CSVImportDialog.js

@@ -457,7 +457,7 @@ class CSVImportPanel extends Component {
                   )}
                   {importResult.errors > 0 && (
                     <Typography variant="body1" color="warning.main">
-                      <strong>Fehler:</strong> {importResult.errors} Zeilen konnten nicht verarbeitet werden
+                      <strong>Fehler:</strong> {importResult.errors} Zeilen konnten nicht verarbeitet werden.
                     </Typography>
                   )}
                   {importResult.message && (

src/routes/data/csvImport.js

@@ -129,6 +129,7 @@ router.post('/test-csv-import', async (req, res) => {
 
 // Import CSV transactions to database
 router.post('/import-csv-transactions', authenticateToken, async (req, res) => {
+  console.log('Importing CSV transactions');
   try {
     const { executeQuery } = require('../../config/database');
     const { transactions, filename, batchId, headers } = req.body;
@@ -180,6 +181,7 @@ router.post('/import-csv-transactions', authenticateToken, async (req, res) => {
     let successCount = 0;
     let errorCount = 0;
     const errors = [];
+    console.log('precheck done');
     
     for (let i = 0; i < transactions.length; i++) {
       const transaction = transactions[i];
@@ -195,9 +197,6 @@ router.post('/import-csv-transactions', authenticateToken, async (req, res) => {
           validationErrors.push('Betrag is required');
         }
         
-        if (!transaction['Beguenstigter/Zahlungspflichtiger'] || transaction['Beguenstigter/Zahlungspflichtiger'].trim() === '') {
-          validationErrors.push('Beguenstigter/Zahlungspflichtiger is required');
-        }
         
         if (validationErrors.length > 2) {
           console.log('Skipping invalid row ' + (i + 1) + ':', validationErrors);
@@ -287,6 +286,8 @@ router.post('/import-csv-transactions', authenticateToken, async (req, res) => {
         errorCount++;
       }
     }
+
+    console.log('import done',errors);
     
     res.json({
       success: true,