Add ValueOrDefault method overload, with Func<T> as argument #169
Description
Currently, Maybe.ValueOrDefault offers only a method with a parameter of type T as a method argument.
If this value T is generated via a create method, T is generated before the "None" check is performed. As a consequence, T is created even if Maybe is not “None”.
The aim is to prevent the function from being executed in the method argument in the non-"None" case.
Therefore Maybe.ValueOrDefault shall be extended by a method overload that accepts Func instead of argument T.
This function should only be executed after the "None" check and only in the "None" case.
Method overloads shall be implemented for Maybe and MaybeStruct.