Merge #11817: [tests] Change feature_csv_activation.py to use BitcoinTestFramework

1298268 [tests] Change feature_csv_activation.py to use BitcoinTestFramework (John Newbery)
db7ffb9 [tests] Move utility functions in feature_csv_activation.py out of class. (John Newbery)
0842edf [tests] Remove nested loops from feature_csv_activation.py (John Newbery)
2e511d5 [tests] improve logging in feature_csv_activation.py (John Newbery)
6f7f5bc [tests] fix flake8 nits in feature_csv_activation.py (John Newbery)

Pull request description:

  Next step in #10603.

  - first four commits tidy up bip68-112-113-p2p.py
  - fifth commit removes usage of ComparisonTestFramework

Tree-SHA512: 34466be12280096ad92ac842f9c594ae40c19be9b4edc73c1e37964d03d55f4e75b80cea50c9940404096effc23705671503a883a7b7773b5866a29f653ba710

Author: MarcoFalke