feat: use TCP/IP emulator for providing access to network

Right now access to network destinations is provided using individual UDP or TCP sockets that are connected / bound inside the hypervisor and passed to partitions using UNIX domain sockets. This has the limitation of only ever allowing existing connections to the target from at the time the hypervisor started. With something like [slirp](https://github.com/rootless-containers/slirp4netns?tab=readme-ov-file) it would be possible to provide a (limited) TCP/IP stack to partitions. This is how QEMU and rootless podman do it by default.