Move m_failed_blocks to ChainstateManager

Summary:
The member is unrelated to block storage (BlockManager). It is related
to validation.

Fix the confusion by moving it.

Can be reviewed with
--color-moved=dimmed-zebra --color-moved-ws=ignore-all-space

This is a partial backport of core#23785
https://github.com/bitcoin/bitcoin/pull/23785/commits/facd2137eceacb95e1f71c87ddc704d752b37272

Depends on D12485

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D12486