Add Cowperthwaite activation logic

Summary:
Add a facility to chack wether the November 15, 2023 upgrade has activated.

Depends on D14051.

Test Plan:

ninja all check

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Subscribers: Mengerian

Differential Revision: https://reviews.bitcoinabc.org/D14062