* update to 5.12.4
* removed port qt5-modularscripts and split it functionality into more functions into qt5-base
* added qt_port_hashes.cmake for simpler upgrade.
* added optional VCPKG_QT_HOST_MKSPEC and VCPKG_QT_TARGET_MKSPEC to select QTs build mkspecs from a triplet
* qt_<config>.conf are now copied from the build dir instead from the port dir
* fixed freetype dependencies.
* cleanup of vcpkg_qmake scripts. No strange/unclear replacements anymore.
* introduced vcpkg_buildpath_length_warning
* changed directory layout of the qt5 installation executables and mkspecs a bit.
