feat: scope cleanup to app when specified

This will require changes in community plugins to properly add the specified labels to intermediate containers.

Closes #3515

plugins/apps/functions

@@ -42,6 +42,7 @@ apps_destroy() {
   plugn trigger scheduler-stop "$DOKKU_SCHEDULER" "$APP" "$REMOVE_CONTAINERS"
   plugn trigger scheduler-post-delete "$DOKKU_SCHEDULER" "$APP" "$IMAGE_TAG"
   plugn trigger post-delete "$APP" "$IMAGE_TAG"
+  docker_cleanup "$APP" "true"
 }
 
 apps_exists() {