Allow mutiple filter strategies per project

[janopae]

Sometimes, different entities have different visibility strategies. However, most of the time multiple entities still share one strategy. There should be a way for mapping different entities to filter strategies. Maybe through the data type of the visibility column?

[sebastiankugler]

If I am not mistaken, I think we wanted to allow the choice of strategy via the annotation.

@visibilityColum would choose the standard strategy of the project, @visibilityColumn(ASpecialStrategy) would declare a deviation from the standard.