Currently it uses GetTimeMicros, which is the system time. Using steady time instead, makes the code type safe and avoids spurious offsets when the system time adjusts.
This is a backport of [[https://github.com/bitcoin/bitcoin/pull/25456 | core#25456]]
The `Tick` helper is a dependency for future backports (starting with [[https://github.com/bitcoin/bitcoin/pull/25717 | core#25717]])