Replace the kieker records with the avro records in uc3 application.

In order to not add a new configuration key that is needed by
all the kafka stream use case applications extract the configuration
keys to the kafkastreams common project.

Replace the kieker records with the avro records in uc2 application.

The Project is renamed to theodolite and therefore all packages
should be renamed likewise.

The use cases extend the KafkaStreamsBuilder and only configure
project specific stuff for the Kafaka streams application.
This reduces in the KafkaStremBuilder classes the redundancy.

Add the spesb prefix to all self implemented java packages of the
project. Because this changes the fully qualified class name of
the main classes the build.gradle files need to adopt to this.