network: firewalld: native support for NAT/routed

Hello I'd like to revive the thread started by Eric Garver at the end of last year that aims to bring native Firewalld support to libvirtd [1]. Currently the Firewalld configuration set up by libvirtd is based on a quirk [2] that makes it a bit puzzling for users. The aforementioned patches implements the same configuration from a Firewalld policy which is much more cleaner and understandable. I'm supportive to move forward on this patch series. Regards Hervé [1] https://listman.redhat.com/archives/libvir-list/2022-November/235725.html [2] https://gitlab.com/libvirt/libvirt/-/commit/3b71f2e42dc6c5453d09136578bfb...