[avalanche] Run the quorum functional test with the new proof format

Summary: There is simply no reason not to do so.

Test Plan:

./test/functional/test_runner.py abc_p2p_avalanche_quorum

Check the test runs with and without the --nolegacyavaproof flag

Reviewers: #bitcoin_abc, sdulfari

Reviewed By: #bitcoin_abc, sdulfari

Differential Revision: https://reviews.bitcoinabc.org/D11660