This changes many different CMake places to mention Qt6 instead of
Qt5.
Note that some old qt5 cmake config files in corelib are probably not
needed anymore, but I still renamed and kept them for now.
Change-Id: Ie69e81540386a5af153f76c0242e18d48211bec4
We'll be adding calendar code here as well, and tools/ was getting
rather crowded, so it looks like time to move out a reasonably
coherent sub-bundle of it all.
Change-Id: I7e8030f38c31aa307f519dd918a43fc44baa6aa1
Reviewed-by: Lars Knoll <lars.knoll@qt.io>