Task improvements (#5159)

* Ignore triggered events if plugin events are not enabled

* Ensure that plugin tasks are handled by the background worker

* Allow shell access

* Don't force async if testing

* Enable plugin events as part of CI

* fix

InvenTree/plugin/samples/event/test_event_sample.py

@@ -3,6 +3,7 @@
 from django.conf import settings
 from django.test import TestCase
 
+from common.models import InvenTreeSetting
 from plugin import InvenTreePlugin, registry
 from plugin.base.event.events import trigger_event
 from plugin.helpers import MixinNotImplementedError
@@ -21,6 +22,8 @@ class EventPluginSampleTests(TestCase):
         config.active = True
         config.save()
 
+        InvenTreeSetting.set_setting('ENABLE_PLUGINS_EVENTS', True, change_user=None)
+
         # Enable event testing
         settings.PLUGIN_TESTING_EVENTS = True
         # Check that an event is issued