Parse function for XSD datatypes for Web service procedures

Defect Tracker #22201: for Web Service procedures and other places where xml document values are incoming, a function such as:

parseXSDType(<string: raw value>, <string: xsdtype>) is needed to convert the raw value into the expected runtime type for the given xsdtype. This alleviates the need for embedding potentially problematic formatting strings into the transformations.

See the logic that was already added for the output side of xsd types for defect 20717.