refactor: move UpdateTip into CChainState

Summary:

Makes sense and saves on arguments.

Completes backport of core#22415:
https://github.com/bitcoin/bitcoin/pull/22415/commits/ceb7b35a39145717e2d9d356fd382bd1f95d2a5a

The last (4th) commit is not relevant as we already have a cleaner solution for UpdateMempoolForReorg (see D1667).

Depends on D12230.

Test Plan:

ninja all check-all

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Subscribers: PiRK

Differential Revision: https://reviews.bitcoinabc.org/D12231