### Description

Recently, we added [a new DAG dependencies view](https://github.com/apache/airflow/pull/13199) to the webserver. It would be helpful if a similar diagram could also be displayed/generated using the CLI. For now, only [one DAG can be displayed](http://airflow.apache.org/docs/apache-airflow/stable/usage-cli.html#exporting-dag-structure-as-an-image) using CLI.
![image](https://user-images.githubusercontent.com/12058428/137945580-6a33f919-2648-4980-bd2c-b40cfcacc9fe.png)

If anyone is interested, I will be happy to help with the review.

### Use case/motivation

* Keep parity between CLI and web serwer.
* Enable the writing of scripts that use these diagrams, e.g. for attaching in the documentation.

### Related issues

https://github.com/apache/airflow/pull/13199/files

### Are you willing to submit a PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

airflow/cli/cli_parser.py
"""Get long option from Arg.flags"""
        return arg.flags[0] if len(arg.flags) == 1 else arg.flags[1]
    positional, optional = partition(lambda x: x.flags[0].startswith("-"), args)
    yield from positional
    yield from sorted(optional, key=lambda x: get_long_option(x).lower())
def _add_command(subparsers: argparse._SubParsersAction, sub: CLICommand) -> None:
    sub_proc = subparsers.add_parser(
        sub.name, help=sub.help, description=sub.description or sub.help, epilog=sub.epilog
    )
    sub_proc.formatter_class = RawTextHelpFormatter
    if isinstance(sub, GroupCommand):
        _add_group_command(sub, sub_proc)
    elif isinstance(sub, ActionCommand):
        _add_action_command(sub, sub_proc)
    else:
        raise AirflowException("Invalid command definition.")
def _add_action_command(sub: ActionCommand, sub_proc: argparse.ArgumentParser) -> None:
    for arg in _sort_args(sub.args):
        arg.add_to_parser(sub_proc)
    sub_proc.set_defaults(func=sub.func)
def _add_group_command(sub: GroupCommand, sub_proc: argparse.ArgumentParser) -> None:
    subcommands = sub.subcommands
    sub_subparsers = sub_proc.add_subparsers(dest="subcommand", metavar="COMMAND")
    sub_subparsers.required = True
    for command in sorted(subcommands, key=lambda x: x.name):
        _add_command(sub_subparsers, command)