Use user configured encoding in receive request

Summary:
The address associated with a receive request is encoded using the
configuration of the client at the time. This can be either base58 or
cashaddr.

When displaying an existing receive request, display with the currently
configured encoding.

Test Plan:

• Added test.
• Create two requests, one running with -usecashaddr and one without.
• Start client with and without -usercashaddr, observe that requests are displayed correct.

Reviewers: #bitcoin_abc, dagurval

Reviewed By: #bitcoin_abc, dagurval

Subscribers: deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D801