[util] Introduce a SetMockTime that takes chrono time
Summary:
This is a backport of core#21121 [4/4]
https://github.com/bitcoin/bitcoin/pull/21121/commits/47a7a1687d276bfa8769dee4bb78e8725f67a50e
https://github.com/bitcoin/bitcoin/pull/21121/commits/1363b6c27dbd2614fd555d148ea624ed8b95f14e
Test Plan: ninja check
Reviewers: #bitcoin_abc, Fabien
Reviewed By: #bitcoin_abc, Fabien
Differential Revision: https://reviews.bitcoinabc.org/D12109