Optionally allow Property Reactive drools rules

If users want to use Property Reactive, they add the @PropertyReactive annotation on their model, but DroolsScoreDirector, still does:
kieSession.update(factHandle, entity);
that must be replaced with
kieSession.update(factHandle, entity, variableName);

Add a test, but keep the examples free from property reactive because most enterprises tend to shoot themselves in the foot with it (a senior programmer enables it, but later, during maintenance changes, a junior programmers forget to adjust @Modifies annotations.