Open Points for Beam benchmark implementations

Remaining things from of #147 (closed) and !187 (merged)

-- TODO: --

• Clear usage of samza configuration. Is this needed with multiple instances for the shared zookeeper state?
• Clear usage of samza pipeline option `--maxSourceParallelism=$MAX_SOURCE_PARALLELISM**
• Clear usage of flink pipeline option --parallelism=$PARALLELISM
• Clear usage of flink pipeline option --flinkMaster=flink-jobmanager:8081
• Clear usage of --fasterCopy
• Clear usage of --enableMetrics=false
• Test implementations in more detail: eg. multiple instances, ...
• Check when a TimestampPolicie is needed.
• Clear usage of Uc2ApplicationBeamNoFeedback.java (old use case 2 / new use case 4).
• Configure Logger to not always log the kafka Subscription State.
• Maybe shorten Uc4Pipeline.
• ConfigurationKeys not optimal
• ENV MAX_SOURCE_PARALLELISM=1024 as default