* configure.ac: Do not look for kf6 native tools on the
build system anymore.
(GPG4WIN_TOOLSPKG): Add new list for native packages
* m4/gpg4win.m4 (GPG4WIN_CHECK_TOOLSDEPS): New.
(GPG4WIN_TOOLSPKG): Main macro for packages which should
be built for the native build system first.
* src/Makefile.am: Add the templates for the packages which
should be built natively.
* src/Makefile.am: Add the configure and post_install actions
as required.
* src/gpg4win.mk.in: Add the make templates for the native
tools and build them first.
* src/toolchain.cmake.in: Use our now known path to KF6
host tooling.