Print all keys and values where key matches PATTERN. Default pattern is * (all keys)

def dump(file_name, pattern):
    """
    Print all keys and values where key matches PATTERN. Default pattern is * (all keys)
    """
    db = XonoticDB.load_path(file_name)
    items = sorted(db.filter(pattern), key=lambda x: natural_sort_key(x[0]))
    for k, v in items:
        click.echo('%s: %s' % (k, v))