profile generation refactoring

refactoring the profile generator.
Filter convention now has a $exist rule
if the value is null.

needs some more examinination if everything is ok.
fixing bugs in profile generation

fixing some bugs in the profile generation.
cleaning up a bit.
refactoring sampling algorithms

refactoring all the sampling alogrithms.
Adding new BetweenFilterCondition and adapting
the filter serializer.
fixing MongoFilterSerializer bug

fixing the filter serializer when serializing or filters.
Test runs again
Merge branch 'enhancement/profile-generation' into integration
Merge branch 'enhancement/sample-selection' into integration