Migrated abc-p2p-fullblocktest.py off of ComparisonTestFramework

Summary: Progress on T669

Test Plan: test_runner.py abc-p2p-fullblocktest

Reviewers: #bitcoin_abc, deadalnix, Fabien

Reviewed By: #bitcoin_abc, Fabien

Maniphest Tasks: T669

Differential Revision: https://reviews.bitcoinabc.org/D3995