Feature: A way to construct a `Network` object for an existing docker network

What are you trying to do?

Attach a DockerContainer to an existing network. In my specific case, the network was created as part of a composable setup, and I'd like to attach a new container to that network.

Why should it be done this way?

I suppose my suggestion would be a way to construct a Network object by simply passing the name in as an argument. Best I can tell that name property is all that is really needed when the DockerContainer is started.

A perhaps easier way might be to create a new class

class ExistingNetwork:
    def __init__(self, network_name: str):
        self.name = network_name

While this I think could be passed into DockerContainer.with_network & it seems to work, it might be better to have this inherit Network and explicitly override the other methods in the Network class to ensure they are not called.

Start with core/testcontainers/core/network.py around the Network name property and inspect DockerContainer.with_network. Determine how an existing network name can be represented without creating or managing the network, then verify that a DockerContainer can attach to it when started.