Use meson to install system-wide directories and files

To be able to install files (e.g. man pages, documentation, system-wide directories) we need to use something else than python-installer as the use of install-data (e.g. as used by python-setuptools) in the context of installing files from a wheel outside of the scope of a site-packages location is deprecated and discouraged.

To install future system-wide files and directories we can make use of e.g. meson to do this for us and also call the build and installation process.

Repod would still remain installable via wheel installer, but it would be incomplete, especially when thinking of system-mode.