Custom network range when using --network-address

### Description
First of all, I would like to thank you for such good project. My company is starting to move away from Docker Desktop to Colima/Rancher Desktop but I personally prefer CLI style so Colima fits my style more.

I'm not sure if this feature is already available or how to do it, but what I would like to do is when creating a new Colima vm with --network-address flag, I would like to customize the network for that. Right now it seems it defaults to 192.168.106.x.
My use case it that when I connected to my company VPN, there's a certain subnet networks I can configure so that traffic won't go to the VPN, but the 192.168.106.x is not in the list and I cannot access the Colima vm when I'm on VPN.