Define categories explicitly

[boolean5]

There is a plan to stop falling back to using the default categories when a configuration section does not have a categories key. Instead, shavar-list-creation will raise a ValueError in this case.

We should go through the configuration files in this repo and make sure that all sections are defining their categories explicitly.

Regarding sections tracking-protection-baseeff and tracking-protection-basew3c, after a discussion with @englehardt and @say-yawn, we decided to remove them, as they are not used anymore.

[say-yawn]

@englehardt can you comment whether or not:

• tracking-protection-contentw3c
• tracking-protection-contenteff
  configs can also be removed?

[englehardt]

@say-yawn We don't use these anymore, so they can be removed.