### 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
dag_ids = [
            'example_bash_operator',  
            'latest_only',  
            'example_python_operator',  
            'example_xcom',
        ]  
        
        with create_session() as session:
            dr = session.query(DagRun).filter(DagRun.dag_id.in_(dag_ids))
            dr.delete(synchronize_session=False)
        
        args = self.parser.parse_args(['dags', 'next-execution', dag_ids[0]])
        with contextlib.redirect_stdout(io.StringIO()) as temp_stdout:
            dag_command.dag_next_execution(args)
            out = temp_stdout.getvalue()
            
            
            assert "None" in out
        
        now = DEFAULT_DATE
        expected_output = [
            (now + timedelta(days=1)).isoformat(),
            (now + timedelta(hours=4)).isoformat(),
            "None",
            "None",
        ]
        expected_output_2 = [
            (now + timedelta(days=1)).isoformat() + os.linesep + (now + timedelta(days=2)).isoformat(),
            (now + timedelta(hours=4)).isoformat() + os.linesep + (now + timedelta(hours=8)).isoformat(),