Hash the input of OP_CHECKDATASIG instead of expecting the user to do it.
This is safer
Co-authored-by: Amaury Séchet <firstname.lastname@example.org>
Co-authored-by: Jason B. Cox <email@example.com>
Test Plan: Updated tests to reflect the change.
Reviewers: #bitcoin_abc, Mengerian, schancel, jasonbcox
Reviewed By: #bitcoin_abc, Mengerian, schancel, jasonbcox
Subscribers: schancel, Mengerian, teamcity
Differential Revision: https://reviews.bitcoinabc.org/D1646