- Fix the `dump_json` method in the `ModelView` class to call `model_dump_json` instead of `model_dump`, ensuring consistency in JSON serialization.
- Added a new test case in `TestListModelView` to verify the functionality of `dump_json` and check for correct IP address serialization.
- Enhanced the `vlans`, `interfaces`, and `system` properties with type hints for better clarity and type checking.
- Added detailed docstrings to each property, describing the return types and structure of the associated configurations.