[FR] paymentAddresses also include the rewards address

[MarcelKlammer]

I wasn't able yet to find a way to get all base addresses (payment key + stake key) that a stake key controls.

Would it be possible to add the stake address (rewards address) to paymentAddresses, so we actual have a mapping and can search from there?

[rhyslbw]

Good suggestion @MarcelKlammer. I will add it to the backlog