BB-4198: Fix issues with package upgrades.
Fixes two issues:
- From Openstack package upgrade: an exception class was removed in favor of a more generic one.
- Bug found while testing: Terminate VM is not a background task, which makes the web worker halt if the VM takes too long to shutdown (moved to a huey task).
This is currently deployed to stage.
Reviewers:
-
Any FFs: @Clemente @symbolist @itsjeyd (high priority review, some Ocim methods are broken on master
without this)