This allows new code, added in the next commit, to conform to the coding
guideline: No C-prefix for class names.
This is a partial backport of [[https://github.com/bitcoin/bitcoin/pull/25284 | core#25284]]
https://github.com/bitcoin/bitcoin/pull/25284/commits/fac42e9d35f6ba046999b2e3a757ab720c51b6bb
Depends on D19054