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.

#
#
from __future__ import annotations
import os
from unittest import mock
import flask
import markupsafe
import pytest
from airflow.dag_processing.processor import DagFileProcessor
from airflow.security import permissions
from airflow.utils.session import create_session
from airflow.utils.state import State
from airflow.www.utils import UIAlert
from airflow.www.views import FILTER_STATUS_COOKIE, FILTER_TAGS_COOKIE
from tests.test_utils.api_connexion_utils import create_user
from tests.test_utils.db import clear_db_dags, clear_db_import_errors, clear_db_serialized_dags
from tests.test_utils.www import check_content_in_response, check_content_not_in_response, client_with_login
def clean_db():