Check if applications are active/idle before upgrading.

- Without status check if the unit is on maintenance it will
  proceed to upgrade

Closes: canonical#199

cou/utils/juju_utils.py

@@ -481,6 +481,7 @@ async def _wait_for_idle() -> None:
                     timeout=timeout,
                     idle_period=idle_period,
                     raise_on_blocked=raise_on_blocked,
+                    status="active",
                 )
             except (asyncio.exceptions.TimeoutError, JujuAppError, JujuUnitError) as error:
                 # NOTE(rgildein): Catching TimeoutError raised as exception when wait_for_idle

tests/unit/utils/test_juju_utils.py

@@ -486,6 +486,7 @@ async def test_coumodel_wait_for_idle(mock_get_supported_apps, mocked_model):
         timeout=timeout,
         idle_period=juju_utils.DEFAULT_MODEL_IDLE_PERIOD,
         raise_on_blocked=False,
+        status="active",
     )
     mock_get_supported_apps.assert_awaited_once_with()
 
@@ -504,6 +505,7 @@ async def test_coumodel_wait_for_idle_apps(mock_get_supported_apps, mocked_model
         timeout=timeout,
         idle_period=juju_utils.DEFAULT_MODEL_IDLE_PERIOD,
         raise_on_blocked=False,
+        status="active",
     )
     mock_get_supported_apps.assert_not_awaited()
 
@@ -525,5 +527,6 @@ async def test_coumodel_wait_for_idle_timeout(mock_get_supported_apps, mocked_mo
         timeout=timeout,
         idle_period=juju_utils.DEFAULT_MODEL_IDLE_PERIOD,
         raise_on_blocked=False,
+        status="active",
     )
     mock_get_supported_apps.assert_not_awaited()