AWS Cloudformation (and by proxy EKS Nodegroup) delete() should block until completed or failed

[lloesche]

Right now during the cleanup phase of AWS resources we mostly just call the delete() method on whatever resource we're trying to remove. For almost all resources this is a blocking call that returns whether or not a resource was succesfully deleted. However Cloudformation always returns success and then the operation status has to be polled to know its status. Those deletes can run for many minutes even hours for complexe environments so waiting for them would currently block resource collection. We could delete a Cloudformation stack and then wait a certain amount of time for the delete to complete before timing out.