[cooker] CMAKE_INSTALL_FULL_LIBEXECDIR_KF5 is not respected

Hi,

i've notced that some KF5 modules are installed into %{_libdir}/libexec/kf5
while completely omits
already set and default path for CMAKE_INSTALL_FULL_LIBEXECDIR_KF5 =
%{_libexecdir}/kf5

see for example kinit:

-- Installing: /builddir/build/BUILDROOT/kinit-5.63.0-1.x86_64/usr/lib64/libexec/kf5/klauncher
-- Installing: /builddir/build/BUILDROOT/kinit-5.63.0-1.x86_64/usr/lib64/libexec/kf5/start_kdeinit
-- Installing: /builddir/build/BUILDROOT/kinit-5.63.0-1.x86_64/usr/lib64/libexec/kf5/start_kdeinit_wrapper

when on %cmake_kde5

-DCMAKE_INSTALL_FULL_LIBEXECDIR=/usr/libexec
-DCMAKE_INSTALL_FULL_LIBEXECDIR_KF5=/usr/libexec/kf5

kpackage is broken because of above

QString candidatePath =
QStringLiteral(CMAKE_INSTALL_FULL_LIBEXECDIR_KF5
"/kpackagehandlers/%1handler").arg(scheme);

so it checks for /usr/libexec/kf5/kpackagehandlers while files are
installed into /usr/lib64/libexec/kf5/kpackagehandlers

This may be the source of below error:
[tpg@tpg-80xl start_kdeinit]$ kcmshell5 kcm_energyinfo
org.kde.kcoreaddons: Error loading plugin "kcm_energyinfo" "The shared
library was not found."
Plugin search paths are ("/usr/lib64/qt5/plugins", "/usr/bin")
The environment variable QT_PLUGIN_PATH might be not correctly set

i have feeling that our kde5.macros are broken

Other distros install stuff into /usr/libexec/.