Init logging

[simonbyrne]

One of the things we typically do in driver scripts is to setup the logging, e.g. ClimaAtmos has:

    if ClimaComms.iamroot(comms_ctx)
        Logging.global_logger(Logging.ConsoleLogger(stderr, Logging.Info))
    else
        Logging.global_logger(Logging.NullLogger())
    end

Should we just fold this into ClimaComms.init()?