* (Qt) Migrate to Qt6
* basic support Qt6 with minimal changes required for compiling
* look `moc` in QT_HOST_LIBEXECS
* (Qt) Backward compatibility with Qt5
* Massive reduction in heap space allocation, going from settings struct
264kb to 119Kb
* Use NAME_MAX_LENGTH for base paths/names, etc
* Use DIR_MAX_LENGTH for directory sizes