validation: add Config to ChainstateManager

Summary:
This is inspired by https://github.com/bitcoin/bitcoin/pull/24595/commits/69675ea4e73dcf5e9dd0f94802bd3463e4262081

I need ChainstateManager.GetConsensus as a dependency of core#25168

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D13244