Add two options: PublicNetwork(UUID) and NetworkMode (Flat, EIP, PortForwarding)
Automatically create an EIP or two PortForwarding rules and attach it/them to created VM, (only) when specified "NetworkMode" is not ZStack FlatNetwork (use EIP or PortForwarding).
The created EIP or PF rules will be deleted when VM is destroyed.
The VIP that created and referenced by EIP or PF rules will be "public address" (rke.cattle.io/external-ip), and the IPv4 address of first NIC of VM will be "private address" (rke.cattle.io/internal-ip)