Read an ordinary (non-e-invoice) PDF invoice and return its data in the input format of create_einvoice: seller and buyer (name, address, VAT ID, country), invoice number, dates, IBAN/BIC, Leitweg-ID and the invoice lines (only if quantity x price and the line sum match the PDF's net total; otherwise one line with the net total). Regex-based, no guessing: fields we can't read reliably are missing and listed in missing. Check and complete them, then call create_einvoice to get XRechnung, ZUGFeRD or Peppol. Scanned PDFs (no text layer) are not supported. Pass the PDF base64-encoded in file_base64. Max 5 MB.