ocflib.infra.net does not support our new subnets

We now have more subnets (a v4 and v6 range at EWDC, a new /24 for VMs); currently, [`ocflib.infra.net`](https://github.com/ocf/ocflib/blob/f44574a264c5139e4559550b8611181e12de9b01/ocflib/infra/net.py) only supports our original subnet.
Also, the v6 subnet is listed as `2607:f140:8801::/48`, but according to socreg we have `2607:f140:8801::/64` and `2607:f140:8800::/48` 🙃 