use different persistence levels for different types.

[zoperado]

Problem
our interface allows to store both
MirrorGetTopicMessages.MirrorGetTopicMessagesResponse.Builder
and
ApplicationMessageChunk

The latter can be derived by the former but it is convenient to allow user to store the more generic type as well.

At the moment, we define a single persistenceLevel in the global config but that level needs to be
split to two in order to define what to keep for both of the above types.

Solution
create persistenceLevelRaw and presistenceLevelChunk in global yaml config

Alternatives
allow only to store the raw message and let the algorithm interpret deal with the interpretation.
Additional layers required to make code readable.