bench: add readblock benchmark
Summary:
This is a backport of core#26684
with renaming changes:
https://github.com/bitcoin/bitcoin/pull/31490/commits/34f9a0157aad7c10ac364b7e4602c5f74c1f9e20
and additional includes from core#30716
Depends on D18952
Test Plan: ninja bench-bitcoin`
Reviewers: #bitcoin_abc, Fabien
Reviewed By: #bitcoin_abc, Fabien
Differential Revision: https://reviews.bitcoinabc.org/D18957