* events: initial alerting implementation
* policies: move error handling to process, ensure policy UUID is saved
* policies: add tests for error handling in PolicyProcess
* events: improve loop detection
* events: add API for action and trigger
* policies: ensure http_request is not used in context
* events: adjust unittests for user handling
* policies/event_matcher: add policy type
* events: add API tests
* events: add middleware tests
* core: make application's provider not required
* outposts: allow blank kubeconfig
* outposts: validate kubeconfig before saving
* api: fix formatting
* stages/invitation: remove invitation_created signal as model_created functions the same
* stages/invitation: ensure created_by is set when creating from API
* events: rebase migrations on master
* events: fix missing Alerts from API
* policies: fix unittests
* events: add tests for alerts
* events: rename from alerting to notifications
* events: add ability to specify severity of notification created
* policies/event_matcher: Add app field to match on event app
* policies/event_matcher: fix EventMatcher not being included in API
* core: use objects.none() when get_queryset is used
* events: use m2m for multiple transports, create notification object in task
* events: add default triggers
* events: fix migrations return value
* events: fix notification_transport not being in the correct queue
* stages/email: allow sending of email without backend
* events: implement sending via webhook + slack/discord + email
