[refactor] Moved org.exist.dom.persistent.QName -> org.exist.dom.QName
Cleanup of QName internal code and renamed getLocalName() ->
getLocalPart()
[clean] Reuse constants from Java standard library where available
Initial pass at making QName immutable
Make the use of Wildcard names explicit. Should ideally be refactored
into NameTest
Fix bug with QName.setNameType which was introduced during QName
refactoring