logging: treat BCLog::ALL like BCLog::NONE
Summary:
This is a partial backport of core#28318
https://github.com/bitcoin/bitcoin/pull/28318/commits/782bb6a05663ad7a53908e910d0f42b49b881e09
Depends on D18272
Test Plan: ninja all check-all
Reviewers: #bitcoin_abc, Fabien
Reviewed By: #bitcoin_abc, Fabien
Differential Revision: https://reviews.bitcoinabc.org/D18273