Enhanced beam-commons for uc3

.../main/java/theodolite/commons/beam/ConfigurationKeys.java

...n/java/theodolite/commons/beam/kafka/EventTimePolicy.java

...c3-beam-flink/src/main/java/application/Uc3BeamFlink.java

...arks/uc3-beam/src/main/java/application/HourOfDayKey.java

...3-beam/src/main/java/application/HourOfDayKeyFactory.java

...uc3-beam/src/main/java/application/HourOfDayKeySerde.java

...uc3-beam/src/main/java/application/HourOfDaykeyCoder.java

...rks/uc3-beam/src/main/java/application/MapTimeFormat.java

.../uc3-beam/src/main/java/application/StatsAggregation.java

...s/uc3-beam/src/main/java/application/StatsKeyFactory.java