### Description

In Airflow UI. If we go to Browse --> DAG Runs, then DAG Runs view will be displayed.

Table contains a lot of insightful values likes DAG execution date, Start date, end date, Dag config etc

Request to add DAG duration column in the same table.
DAG Duration i.e. DAG end_date timestamp  - DAG start_date timestamp

### Use case/motivation

Analytics purpose of knowing DAG duration at all DAGs level. So that I can easily find out which DAG  have least and max duration.

### Related issues

Checked open issues. There aren't any

### 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/www/views.py
error_message = (
                f'Given execution date, {execution_date}, could not be identified as a date. '
                'Example date format: 2015-11-16T14:34:15+00:00'
            )
            response = jsonify({'error': error_message})
            response.status_code = 400
            return response
        task_log_reader = TaskLogReader()
        if not task_log_reader.supports_read:
            return jsonify(
                message="Task log handler does not support read logs.",
                error=True,
                metadata={"end_of_log": True},
            )
        ti = (
            session.query(models.TaskInstance)
            .filter(
                models.TaskInstance.dag_id == dag_id,
                models.TaskInstance.task_id == task_id,
                models.TaskInstance.execution_date == execution_date,
            )
            .first()
        )
        if ti is None:
            return jsonify(
                message="*** Task instance did not exist in the DB\n",
                error=True,
                metadata={"end_of_log": True},
            )
        try: