[ChangeLog][QtQuick] Fixed TextInput to call fixup() on its validator
when being accepted or losing focus, and the validator reports that the
input is in "intermediate" state ie. the input should be fixed up.

Task-number: QTBUG-35128
Change-Id: I4b15406c584a9647bcf892badfaf6d845868fbf1
Reviewed-by: Liang Qi <liang.qi@digia.com>