On master (d6fe5b28dff4c512bad7c9576232d6def10608d4):

With this PR:

This is a move-only change.
This was done while reviewing #15.
Concept ACK
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Rebased c32b53fd13be47167051516b3e9df7a130db39b1 -> 6ed4bcabc1a9103efb96685c447c07d0d2d2e0e0 (pr20.01 -> pr20.02) due to the conflict with https://github.com/bitcoin/bitcoin/pull/19210.
utACK 6ed4bcabc1a9103efb96685c447c07d0d2d2e0e0