QStringLiteral is broken in MSVC2015 onwards when used with \uXXXX
encoded character literals. This was the reason Japanese tests were
failing - the OpenWNN engine was actually broken and producing
garbage.

Not only this change eliminates QStringLiteral from openwnn, but also
reduces runtime memory usage by replacing QMap<QString, QString>.

The new solution is based on simple binary lookup table WnnLookupTable.
WnnLookupTable data was converted from existing QMap structures using
WnnLookupTable::create() method, which was left there for future
reference.

This change also removes the unnecessary QObjectPrivate definitions
from Romkan* classes.

[ChangeLog][OpenWNN] Fixed and optimized OpenWNN engine (as a workaround
for QStringLiteral breakage)

Task-number: QTBUG-62133
Change-Id: I50c9e2f5c363e1314f47d7023685da543ec9a7eb
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>
(cherry picked from commit 0bf1c6ad)