feat: include bank account in booking data

src/BusProNet/DataProcessor/BookingDataProcessor.php

@@ -132,6 +132,15 @@ class BookingDataProcessor
             ],
         ];
 
+        if (null !== $bookingData->bankAccount) {
+            $payload['zahlung']['bankverbindung'] = [
+                '@kreditinstitut' => $bookingData->bankAccount->bankName,
+                '@iban' => $bookingData->bankAccount->iban,
+                '@bic' => $bookingData->bankAccount->bic,
+                '@kontoinhaber' => $bookingData->bankAccount->holder,
+            ];
+        }
+
         foreach ($bookingData->participants as $index => $participant) {
             $payload['teilnehmerliste']['teilnehmer'][] = [
                 '@id' => $index,