[Validator] ProfileAssertion depends on IElementNav.Type being populated

[ewoutkramer]

ProfileAssertion uses IEN.Type in its decision logic, but.....

If IElemenNav is coming straight from an xml or json file, there is most probably no type information (as this is not present on the wire). Make sure that if IEN.Type == null, we derive it from the element name or somesuch.

[mmsmits]

This is not relevant anymore.