Tests: Added --mingw option and better usage of NUITKA_EXTRA_OPTIONS
Tests: Added --mingw option and better usage of NUITKA_EXTRA_OPTIONS

* You can provide these from the outside.

* Also avoid messages for uninstalled Python suites not asked to execute.

kayhayen/Nuitka,kayhayen/Nuitka,kayhayen/Nuitka,kayhayen/Nuitka