E.g. a group separator, a -/+ sign, or 'e' (exponent). Input ending with
one of these characters now returns Intermediate, as it can become
Acceptable if the user types more characters.
Remove a check from initialResultCheck(), as it's now covered by
QLocaleData::validateChars() checking that the last character in the
buffer is -/+, this works the same if buffer's size is 1.
Extended unittests based on the linked bug report; the other cases for
"last" are already covered by existing unittests.
Task-number: QTBUG-111371
Change-Id: I9b6979c29f07a5f57b040004cd3dbf4e27147c21
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
f107773742