Add JUnit Tests:

- Add Pipeline Test for UC1 Hazelcast Jet Pipeline
- Add Pipeline Test for UC2 Hazelcast Jet Pipeline
- Add Pipeline Test for UC3 Hazelcast Jet Pipeline
- ERROR Could not get to work UC4 Hazelcast Jet Pipeline!

Hazelcast Jet Benchmark Operator:

- Add Benchmark Operator Draft for UC1, UC2, UC3, UC4
- Change folder structure of kubernetes definitions for UC1, UC2, UC3, UC4

Hazelcast Jet Benchmark Implementation:

- Rework PipelineBuilder UC1
- Rework PipelineBuilder UC2
- Rework PipelineBuilder UC3
- Rework PipelineBuilder UC4

Ran first tests of new implementations and fixed Checkstyle and PMD errors.

Open/Known Problems:
- UC4 Pipeline test throws error hard to identify
- Kubernetes/Benchmark implementation needs testing