[avalanche] Test: Simplify checking for undesired hashes in polls

Summary: So far we used a custom solution in abc_p2p_avalanche_transaction_finalization.py to against undesired polls. We can greatly simplify this is and make it more reusable by making this an option in the common avatools function.

Test Plan:

./test/functional/test_runner.py abc_p2p_avalanche_transaction_finalization

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Differential Revision: https://reviews.bitcoinabc.org/D17929