SQLite does not provide a proper case folding for non-ascii characters
due to a lack of a proper ICU library. Therefore add an option so Qt can
do it for SQLite.
[ChangeLog][SQL][SQLite] Add new option
QSQLITE_ENABLE_NON_ASCII_CASE_FOLDING for correct case folding of
non-ascii characters.
Fixes: QTBUG-18871
Change-Id: Ib62fedf750f05e50a581604253cf30d81e367b42
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>