cmake-gui: Restore support for internationalization with Qt5 on Windows

Brad Kingrequested to merge
brad.king/cmake:cmake-gui-locale into master

Restore the logic removed by commit 035078d8 from !5621 (merged), but only with Qt5 on Windows. Leave a FIXME comment to support Qt6 later.

Fixes: #23562 (closed)
Issue: #23565 (closed)
Backport: release

Merge request reports