[avalanche] Don't send peers with no node attached in compact proofs

Summary:
This doesn't prevent relaying as inventory but it ensures a smooth cleanup of the dangling proofs after the remote proofs are in use. As a consequence we compare the compact proofs with the peer set to determine what is missing from our remote.

Depends on D14679.

Test Plan:

ninja all check-all

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Differential Revision: https://reviews.bitcoinabc.org/D14680