For unconfirmed commit tx anchors, supply the sweeper with cpfp info and
a confirmation target fee estimate.
The sweeper will try to pay for the parent commit tx as long as the
current fee estimate exceeds the pre-signed commit tx fee rate.
These tests exercise the different ways of sweeping a commitment, so
we'll cover the modified scripts used for anchor commitments and
spending the anchor itself by both parties.
Co-authored-by: Johan T. Halseth <johanth@gmail.com>
