[qa] Fix bip65-cltv-p2p to be compatible with magnetic anomaly

Summary:
Make bip65-cltv-p2p compliant with magnetic anomaly rules.
Remove magneticanomalyactivationtime in future and add tx padding when required.

Depends on D2120

Test Plan:

./test/functional/test_runner.py bip65-cltv-p2p

Reviewers: #bitcoin_abc, deadalnix, jasonbcox

Reviewed By: #bitcoin_abc, deadalnix, jasonbcox

Subscribers: jasonbcox, deadalnix, teamcity

Differential Revision: https://reviews.bitcoinabc.org/D2116