* 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.
* update CONTROL files and version variable
* fix qt5 linkage in debug
* revert target_link_libraries to set_property
* revert mqtt to 5.12.1 since 5.12.3 is not released yet
* update mqtt to 5.12.3
* update hashes
* remove unnecessary patch
* fix qmldevtools debug linkage for qt5-tools
* [qt5-modularscripts] Split build steps
When building modules not available from the vendor download side, the
build process stays the same. Create two functions, one for accessing
the sources, the other for compilation.
* [qtmqtt] Add new port (#5736)
