Create a way to call benchmark's Cleanup function on provisioned VMs

Comments suggest that running in stages allows executing a benchmark multiple times on the same resources. Benchmarks like cassandra_ycsb start a cluster in Prepare and tear it down in Cleanup, so these stages need to be repeated like so:

Provision
Prepare
Run
Cleanup
Prepare
Run
Cleanup
Teardown

However, Cleanup is never executed on provisioned VMs unless the benchmark specifically requires it (typically for cleaning up resources external to the VM that actually cost the user money, as in the object_storage_service benchmark).