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.

"""Client for User that can only access the first DAG from TEST_FILTER_DAG_IDS"""
    return client_with_login(
        app,
        username="user_single_dag",
        password="user_single_dag",
    )
@pytest.fixture(scope="module")
def user_single_dag_edit(app):
    """Create User that can edit DAG resource only a single DAG"""
    return create_user(
        app,
        username="user_single_dag_edit",
        role_name="role_single_dag",
        permissions=[
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_WEBSITE),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_EDIT, permissions.resource_name_for_dag("filter_test_1")),
        ],
    )
@pytest.fixture()
def client_single_dag_edit(app, user_single_dag_edit):
    """Client for User that can only edit the first DAG from TEST_FILTER_DAG_IDS"""
    return client_with_login(
        app,
        username="user_single_dag_edit",
        password="user_single_dag_edit",
    )
TEST_FILTER_DAG_IDS = ["filter_test_1", "filter_test_2", "a_first_dag_id_asc", "filter.test"]
TEST_TAGS = ["example", "test", "team", "group"]
def _process_file(file_path, session):