stats: 1.0.0 - Foreign stats are ignored during deserialization

stats: 1.0.0 - Foreign stats are ignored during deserialization

* Added a strongly typed mapping for the allowed known ``StatisticsType``'s
  for incomming messages.
* Unknown types therefore trigger a `DeserializationException`, before
  they can be processed and filtered by the application.
* Configured the `LogAndContinueExceptionHandler` as
  `default.deserialization.exception.handler`, therefore effectively
  ignoring the foreign messages of unknown type.