https://github.com/apache/airflow/pull/27892 added Internal API as part of Webserver.

We need to introduce `airlfow internal-api` CLI command that starts Internal API as a independent component.
"""Creates and returns command line argument parser."""
    parser = DefaultHelpParser(prog="airflow", formatter_class=AirflowHelpFormatter)
    subparsers = parser.add_subparsers(dest="subcommand", metavar="GROUP_OR_COMMAND")
    subparsers.required = True
    command_dict = DAG_CLI_DICT if dag_parser else ALL_COMMANDS_DICT
    subparser_list = command_dict.keys()
    sub_name: str
    for sub_name in sorted(subparser_list):
        sub: CLICommand = command_dict[sub_name]
        _add_command(subparsers, sub)
    return parser
def _sort_args(args: Iterable[Arg]) -> Iterable[Arg]:
    """Sort subcommand optional args, keep positional args."""
    def get_long_option(arg: Arg):