Add MobilePay payment method

[rvdsteege]

From customer:

I am trying to include MobilePay as a payment method for Denmark, but it seems that your plug-in does not support it. Is this true?

If it is, I would like to know, if you are planning to add it to the pronamic plug-in? Do you have it in your roadmap?

• https://docs.adyen.com/payment-methods/mobilepay/web-drop-in

Internal Help Scout ticket: https://secure.helpscout.net/conversation/2044609529/24656

[rvdsteege]

⏳ Waiting for @remcotolsma to restore push access for https://github.com/pronamic/wp-pay-core to add core payment method.