Allow customizable IP range when creating a new enclave

[0xalex88]

Background & motivation

When trying to create a new enclave on a pc with a home network with CIDR 172.16.0.0/20 the default network allocator uses an overlapping IP range making the enclave creation fail (DNS requests try to go to the router at 172.16.0.1 but fail because it's within the docker network range).
The workaround is to create a placeholder network

docker network create --config-only --subnet 17.16.0.0/20 placeholder

to avoid having a network allocated in the same IP range.

Desired behaviour

It would be nice to either make the network range configurable (either via CIDR or specifying an existing docker network) or exclude network ranges used by interfaces (not sure if possible)

How important is this to you?

Nice to have; this feature would make using Kurtosis more enjoyable.

What area of the product does this pertain to?

CLI: the Command Line Interface