Implement negation of query filter closer to underlying API. Previously andNot() negated the whole filter and it's usage in IsUnique was actually a misunderstanding. Having not() as in javax.persistence.criteria.Predicate seems to be more intuitive for negating the whole filter and more flexible.

{
    "messungsId": 1200,
    "messgroesseId": 242,
    "messwert":1,
    "messwertNwg":"",
    "messfehler":1,
    "nwgZuMesswert":3,
    "mehId":207,
    "grenzwertueberschreitung":false
}