This leaves a very simple script that delegates the heavy configure work
to a CMake script.
This also removes the Makefile templates that were used for
bootstrapping qmake.
Task-number: QTBUG-88742
Change-Id: Iab9c477e0bb611d680bda2cf8aaa7ad88356a8d1
Reviewed-by: Kai Koehne <kai.koehne@qt.io>