Cleanup and restructuring code

execution/infrastructure/grafana/values.yaml

execution/uc2-application/aggregation-deployment.yaml

execution/uc2-workload-generator/deployment.yaml

.../java/theodolite/uc1/workloadgenerator/LoadGenerator.java

...c/main/java/theodolite/kafkasender/KafkaRecordSender.java

.../java/theodolite/uc2/workloadgenerator/LoadGenerator.java

.../java/theodolite/uc3/workloadgenerator/LoadGenerator.java

.../java/theodolite/uc4/workloadgenerator/LoadGenerator.java

...loadgeneration/communication/kafka/KafkaRecordSender.java

...neration/communication/zookeeper/WorkloadDistributor.java

...kloadgeneration/generators/AbstractWorkloadGenerator.java

...workloadgeneration/generators/KafkaWorkloadGenerator.java

...dgeneration/generators/KafkaWorkloadGeneratorBuilder.java

...e/commons/workloadgeneration/misc/WorkloadDefinition.java

...olite/commons/workloadgeneration/misc/WorkloadEntity.java

...theodolite/commons/workloadgeneration/misc/ZooKeeper.java