```
We don't have a project style for ordering class members, but it always
makes sense to have no more than one of each public/protected/private
specifier.
Also move documentation for MaybeDiscourageAndDisconnect to the header.
```
Backport of core PR19791 (1/9):
https://github.com/bitcoin/bitcoin/pull/19791/commits/824bbd1ffba3df7ffa6f5bfaa31298cd484473b1