Block arrival information (and the preciousblock RPC, a related concept) are
both chainstate-agnostic, so these are moved to ChainstateManager. This should
just be a refactor, without any observable behavior changes.
This is a partial backport of core#27746
https://github.com/bitcoin/bitcoin/pull/27746/commits/471da5f6e74bac71aeffe2ebc5faff145a6cbcea
Depends on D17432
Note that nBlockSequenceId is atomic since D1958 (so we bypassed core#22824), and cs_main is not really needed when resetting it. But better to keep the lock in case future backports add more code to `ResetBlockSequenceCounters` (this is called only in tests)