### 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)

tests/cli/commands/test_dag_command.py
'backfill',
                        'example_bash_operator',
                        '--task-regex',
                        'runme_0',
                        '--dry-run',
                        '--start-date',
                        DEFAULT_DATE.isoformat(),
                    ]
                ),
                dag=dag,
            )
        output = stdout.getvalue()
        assert f"Dry run of DAG example_bash_operator on {DEFAULT_DATE.isoformat()}\n" in output
        assert "Task runme_0\n" in output
        mock_run.assert_not_called()  
        dag_command.dag_backfill(
            self.parser.parse_args(
                [
                    'dags',
                    'backfill',
                    'example_bash_operator',
                    '--dry-run',
                    '--start-date',
                    DEFAULT_DATE.isoformat(),
                ]
            ),
            dag=dag,
        )
        mock_run.assert_not_called()  
        dag_command.dag_backfill(