New `--log-list-categories` command line argument to list all available
logging categories. This improves documentation of logging, allowing
users to understand what logging categories are available for use. It is
also useful for developers to understand what logging categories already
exist before making a change.
Implemented using static initializers to register all logrefs on startup.
Ref #141754
Pull Request: https://projects.blender.org/blender/blender/pulls/146456
f7e7a5d09e