Performance testing of Redis in k8s

As part of &619, we want to be able to run performance tests against Redis in K8s and compare to VMs.

We can also reuse this later when it comes to testing read behaviour during failovers.

@cmiskell and @qmnguyen0711 already did a lot of work in #1346 (closed) for testing Redis Cluster, so I should be able to reuse that, adapting if needed.