ParameterUtils can when the value is "" can better return the defaultValue, even if the returnType is a String

The problem is that with hst:parameternames and hst:parametervalues in combination with the TC, that for for example Booleans, Integers, etc, when there is no value applied, the value is "". Then, not the default value from the interface is returned, but in case of boolean false and in case of integer 0. This seems undesirable to me: Only in case of String, it should return "", otherwise, the default value