The DAGs main page has All/Active/Paused.

It would be nice if we can have also Running Now which will show all the DAGs that have at least 1 in Running of DAG runs:
![Screen Shot 2021-08-25 at 11 30 55](https://user-images.githubusercontent.com/62940116/130756490-647dc664-7528-4eb7-b4d8-515577f7e6bb.png)


For the above example the new DAGs tab of Running Now should show only 2 rows.
The use case is to see easily what DAGs are currently in progress.

if TriggererJobRunner.is_needed():
            kwargs["triggerer_job"] = lazy_object_proxy.Proxy(TriggererJobRunner.most_recent_job)
        return super().render_template(
            *args,
            
            scheduler_job=lazy_object_proxy.Proxy(SchedulerJobRunner.most_recent_job),
            **kwargs,
        )
class Airflow(AirflowBaseView):
    """Main Airflow application."""
    @expose("/health")
    def health(self):