Align package structure among all benchmark implementations
The package structure in each Gradle project should be as follow:
rocks.theodolite.benchmarks.<uc1-4>.<kstreams|flink|beam|beam.flink|beam.samza|hazelcastjet|commons>rocks.theodolite.benchmarks.commons.<kstreams|flink|beam|beam.flink|beam.samza|hazelcastjet>rocks.theodolite.benchmarks.loadgenerator
With changing these packages, we might also need to do some refactoring in Dockerfiles, Docker Compose files and Kubernetes resource files (whenever we refer to classes by their name).