EPC (SEPA) bank transfer QR codes put the reference and message on the right lines

The EPC069-12 standard requires the purpose-code line to be present even when it is empty. The generator skipped it, so the payment reference moved onto the purpose line and the message onto the reference line; banking apps may reject such a code or show the wrong remittance information.

Create, edit and the scan page now share one EPC builder. It also checks field lengths, the IBAN without spaces, the EUR amount format and the total size limit.