[avalanche] Let buildavalancheproof take a payout address

Summary:
This address is then derived into a script and added to the generated proof if the -legacyavaproof flag is unset.

Ref T1676.

Depends on D10109.

Test Plan:

ninja all check-all

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Maniphest Tasks: T1676

Differential Revision: https://reviews.bitcoinabc.org/D10133