type-annotation(item as item()) ==> xs:QName
This function takes an item as argument.
If the argument is an element or attribute node, the function returns the type annotation of the node, as a QName. If the type is anonymous, this will be a system-generated internal name.
If the argument is a document node, the function returns xs:anyType if the document has been
schema-validated, or xs:untyped otherwise.
For a text node, the function returns xs:untypedAtomic, and for comment, processing-instruction, and namespace nodes,
it returns xs:string.
If the argument is an atomic value, the function returns the type label of the atomic value, again as a QName.
The prefix of the returned QName should not be treated as significant.
