logging: make [cat:debug] and [info] implicit

Summary:
This is a partial backport of core#28318
https://github.com/bitcoin/bitcoin/pull/28318/commits/dfe98b6874da04e45f68d17575c1e8a5431ca9bc

Depends on D18269

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D18270