LegacyPaymentDataService should return payment data for the data blob in donation/membership when given a payment id. There is common data (amount as int, interval as int, payment type as string) and payment-specific data as array:

• Paypal and Credit card: Existing array of getLegacyData + completed state
• Direct Debit: IBAN, and BIC, plus account number, bank number and bank name, generated by`BankDataGenerator`, canceled state
• Sofort: transaction id, bank transfer code, valuation date, completed state
• Bank transfer: bank transfer code

Keep in mind that anonymised sofort, direct debit and bank transfer payments must return an empty array

Look at the existing field names in the donation DomainToLegacyConverter and use those as array keys