Add the `--github-user-id` option to `coder users list`, which makes the
command only return users with a matching GitHub user id. This will
enable https://github.com/coder/start-workspace-action to find a Coder
user that corresponds to a GitHub user requesting to start a workspace.
This change reduces the CPU consumption of --help by ~50%.
Also, this change removes ANSI escape codes from our golden files. I
don't think those were worth the inability to parallelize golden file tests and
global state fragility.