Add support for lambdas as field pointers

[kotovdv]

Rule<AttractionVisitor> weightTestRule = ensureThat(AttractionVisitor.class)
                .field("weight")
                .isLessThan(100)
                .build();

Rule<AttractionVisitor> weightTestRule = ensureThat(AttractionVisitor.class)
                .field(AttractionVisitor::getWeight)
                .isLessThan(100)
                .build();