[backport#16898] test: Reformat python imports to aid scripted diff

Summary:
https://github.com/bitcoin/bitcoin/pull/16898/commits/1111bb91f517838e5b9f778bf6b5a9c8d561e857

Partial backport of Core PR16898

Test Plan:

ninja
./test/functional/test_runner.py abc-parkedchain.py abc_p2p_compactblocks.py feature_notifications.py

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D6386