Switch to DirectWrite font database by default

There are a few features which we currently cannot support on GDI, which is getting very outdated. We should finally take the step and make DirectWrite the default in Qt 6.7, with gdi as a fallback in case of regressions.

Things that need to be handled:
1. Bitmap fonts have to be added to the database and specially handled by creating GDI font engines
2. We need to check the font family lists on different languages to check that we get the same set (maybe we need to add some aliases manually)
3. Need to check that the default fonts are still resolved the same