test: chainstate write test for periodic chainstate flush

Summary:
This is a partial backport of core#30611
https://github.com/bitcoin/bitcoin/pull/30611/commits/0ad7d7abdbcffc11a46413545a214a716f56dc95
Depends on D18638

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D18639