To make it easier to write .spec files in Cenbuild with meson, we should add appropriate macros like have with other build tools.
This was completed as part of fixing bug 8156. To verify that the macros work, I found an example project [1] that utilizes all macros and was successful in building an RPM for it. [1] https://gitlab.com/twdev_projects/libmagick
We probably want to add macros for ninja as well.
The macros have been updated to be easier to use in Cenbuild. Ninja should now never be called explicitly, and cross-compilation configuration should be loaded automatically.
The macros look very nice. Tested when building pixman, which is available in all platforms. The macros give very clean .spec files with no extra input required by packagers.
