[avalanche] Determine proof acceptance status from the peer manager

Summary:
Rather than supplying the acceptance status to addProofToReconcile(), extract it from the peer manager.

Ref T1854.

Depends on D10377.

Test Plan:

ninja check-avalanche

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Subscribers: deadalnix

Maniphest Tasks: T1854

Differential Revision: https://reviews.bitcoinabc.org/D10378