[avalanche] Request compact proofs from our avalanche outbound peers

Summary:
This sends a getavaproofs message upon connection of an avalanche outbound peer or manually added peer with avalanche enabled.

Depends on D11533.

Test Plan:

ninja all check-all

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Subscribers: deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D11549