Replace anonymous classes creation with lambdas in tests

[panic08]

This change will reduce the amount of code in the tests and simplify it in places where the method implementation is too small, such as:

        new FieldNamingStrategy() {
          @Override
          public String translateName(Field f) {
            return "test";
          }
        }

can be replaced by:
f -> “test”

[eamonnmcmanus]

Thanks, that's a big improvement in readability!