Add support for payment method Direct Debit without payments

[jjeising]

amazon.de (and maybe others) support direct debit as a payment method. In this case the payment method is listed as

Direct Debit | Last digits: XX

but no transactions are listed: strategy_1 fails, as there are no transactions, strategy_2 fails, as the payment amounts are missing: https://github.com/philipmulcahy/azad/blob/45bcf99d06d26cfe54b069e1081aef9098ab3493/src/js/extraction.ts#L103-L106