Feature Request: Allow Network Mode Selection in Container Structure Test

## Description

With recent Docker installations, the default network mode is bridge, which prevents requests to networks not connected to the bridge. When using container-structure-test to send curl requests to different services, this limitation can cause issues.

Would it be possible to add an option to specify the desired network mode when running container-structure-test? This would allow users to configure a network mode that suits their testing environment, such as host or a custom network.

## Expected Behavior

- A new flag or configuration option to specify the network mode (--network similar to docker run).
- Users can set host, bridge, or any custom network as needed.

## Actual Behavior

- Currently, the default bridge mode restricts network access, preventing some requests from working as expected.
- No built-in option to override the network mode.

## Use Case

- This feature would benefit users testing containers that need access to external services, databases, or APIs that are not within the default bridge network.

Would this be a feasible addition to the tool? Thanks!