WIP: Meson: Add python implementation of glib-compile-resources

When cross compiling GTK with GLib as subproject it is still required to have glib tools installed on the build machine which is not convenient on Windows for example. Implementing those tools in python3 means they are arch independent and can be run from GLib subproject.

This is the bare minimum needed by Meson's gnome.compile_resources(), the native implementation supports many more command line arguments.

Helps: #1859