Support for nftables

[fbuetler]

At the moment only iptables are supported and it would be nice if nftables were supported as well.

[awlx]

@DasSkelett maybe we can switch to use netlink for nftables programming that's even possible on machines which don't have nftables binaries.

https://github.com/google/nftables

[DasSkelett]

Yeah I tried adding nftables support with that library in the past, but in the end the rule building was too low-level for my liking, see for example:
https://github.com/siderolabs/talos/blob/dea17d72340b1deddea2215b556a4f193d1feb7f/internal/app/machined/pkg/controllers/kubespan/nftables.go#L181-L223

I might give it another triy, but it will definitely decrease maintainability and expandability of this part of the code.