### 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/utils/test_dot_renderer.py
def setup_class(self):
        clear_db_dags()
    def teardown_method(self):
        clear_db_dags()
    def test_should_render_dag(self):
        with DAG(dag_id="DAG_ID") as dag:
            task_1 = BashOperator(start_date=START_DATE, task_id="first", bash_command="echo 1")
            task_2 = BashOperator(start_date=START_DATE, task_id="second", bash_command="echo 1")
            task_3 = PythonOperator(start_date=START_DATE, task_id="third", python_callable=mock.MagicMock())
            task_1 >> task_2
            task_1 >> task_3
        dot = dot_renderer.render_dag(dag)
        source = dot.source
        
        assert "label=DAG_ID" in source
        assert "first" in source
        assert "second" in source
        assert "third" in source
        assert "first -> second" in source
        assert "first -> third" in source
        assert 'fillcolor="#f0ede4"' in source
        assert 'fillcolor="#f0ede4"' in source
    def test_should_render_dag_with_task_instances(self, session, dag_maker):