Kubernetes files are not adapted to new workload generator

With !6 (merged), a distributed workload generator was added. However, the Kubernetes deployment does not consider this and, in the case of benchmarks UC2 and UC4, does not create enough instances of the workload generator.

Furthermore, workload generator pods for UC1 and UC3 are still created as StatefulSets and not as Deployments, which not be required anymore.