Use payment_instrument_id instead of payment_instrument to calculate payment penalty for existing contribution matcher

[GFF-DS]

Currently, the existing contribution matcher uses a field btx.payment_instrument to calculate payment penalty:

org.project60.banking/CRM/Banking/PluginImpl/Matcher/ExistingContribution.php

Line 246 in 4be17a2

&& isset($parsed_data['payment_instrument'])) {

The field btx.payment_instrument has to be filled with the name of the payment instrument. That's error prone, as a payment instrument may be renamed.

I think, the payment penalty should be calculated against the payment instrument id.

For backward compatibility, this should be configurable.