Make serialization support List[Any] and Map[String, Any]

The instantiate method in class instance builder was explicitly failing when the known target type is Object. 
AFAIK this happens when a generic type gets erased or when we provide a high level type such as Any.

I modified it to:
* provide the wrapped value in case of simple type (e.g., JString, JInt, etc) 
* instantiate objects that have type hints

This makes 4 newly introduced tests pass.