- Part of work for #460.
- Enable set/get of IPv6 network prefix in ReservedVmnetNetwork.
- Show IPv6 prefix in `network list` full output.
- Option for setting IPv6 prefix when creating a network.
- System property for default IPv6 prefix.
## Type of Change
- [ ] Bug fix
- [x] New feature
- [ ] Breaking change
- [x] Documentation update
## Motivation and Context
See #460.
## Testing
- [x] Tested locally
- [ ] Added/updated tests
- [x] Added/updated docs
- Part of work for #460.
- With CZ release 0.17.0, the IP and CIDR address
types changed from String to IPv4Address and
CIDRv4, respectively. This PR applies the corresponding
adaptations to container.