Port ebpf_exporter to Windows

[rob-scheepens]

Now that Microsoft is working on implementing eBPF on Windows (https://github.com/microsoft/ebpf-for-windows), it would be nice to have ebpf_exporter also on Windows, for increased observability. As the implementation is libbpf-based, this seems to tie in with work on supporting libbpf/CORE (#130). I created a related issue on microsoft/ebpf-for-windows#730.

[bobrik]

As long as libbpf and libbpfgo support it, I don't think there would be much (or maybe any) work to support it here.