### 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
func=lazy_load_command('airflow.cli.commands.connection_command.connections_list'),
        args=(ARG_OUTPUT, ARG_VERBOSE, ARG_CONN_ID_FILTER),
    ),
    ActionCommand(
        name='add',
        help='Add a connection',
        func=lazy_load_command('airflow.cli.commands.connection_command.connections_add'),
        args=(ARG_CONN_ID, ARG_CONN_URI, ARG_CONN_EXTRA) + tuple(ALTERNATIVE_CONN_SPECS_ARGS),
    ),
    ActionCommand(
        name='delete',
        help='Delete a connection',
        func=lazy_load_command('airflow.cli.commands.connection_command.connections_delete'),
        args=(ARG_CONN_ID, ARG_COLOR),
    ),
    ActionCommand(
        name='export',
        help='Export all connections',
        description=(
            "All connections can be exported in STDOUT using the following command:\n"
            "airflow connections export -\n"
            "The file format can be determined by the provided file extension. eg, The following "
            "command will export the connections in JSON format:\n"
            "airflow connections export /tmp/connections.json\n"
            "The --format parameter can be used to mention the connections format. eg, "
            "the default format is JSON in STDOUT mode, which can be overridden using: \n"
            "airflow connections export - --format yaml\n"
            "The --format parameter can also be used for the files, for example:\n"
            "airflow connections export /tmp/connections --format json\n"
        ),