### Description

Add DagProcessor status including latest heartbeat to health endpoint similar to Triggerer status added recently. Related PRs.

https://github.com/apache/airflow/pull/31529
https://github.com/apache/airflow/pull/27755

### Use case/motivation

It helps in dag processor monitoring 

### Related issues

_No response_

### Are you willing to submit a PR?

- [X] 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)

latest_scheduler_job = SchedulerJobRunner.most_recent_job()
        if latest_scheduler_job:
            latest_scheduler_heartbeat = latest_scheduler_job.latest_heartbeat.isoformat()
            if latest_scheduler_job.is_alive():
                scheduler_status = HEALTHY
    except Exception:
        metadatabase_status = UNHEALTHY
    try:
        latest_triggerer_job = TriggererJobRunner.most_recent_job()
        if latest_triggerer_job:
            latest_triggerer_heartbeat = latest_triggerer_job.latest_heartbeat.isoformat()
            if latest_triggerer_job.is_alive():
                triggerer_status = HEALTHY
        else:
            triggerer_status = None
    except Exception:
        metadatabase_status = UNHEALTHY
    airflow_health_status = {
        "metadatabase": {"status": metadatabase_status},
        "scheduler": {
            "status": scheduler_status,
            "latest_scheduler_heartbeat": latest_scheduler_heartbeat,
        },
        "triggerer": {
            "status": triggerer_status,
            "latest_triggerer_heartbeat": latest_triggerer_heartbeat,
        },
    }
    return airflow_health_status