log: Move validation option logging to LoadChainstate()

Summary:

This would allow libbitcoinkernel users to see the options logged as well. Currently they would only be logged for bitcoind.

This is a backport of core#25951

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D14657