use existing chainstate reference in various places

Summary:
This removes calls to the global chainstate in Bitcoin ABC specific code that was missed by previous core backports.

Also fix a few linting/autoformatting errors that were somehow introduced and not picked up by arc lint in D11686

Depends on D11737

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D11739