- Replaced the internal `_expand_vlan_range` function in the `Eltex` class with the new `expand_vlan_range` utility from `utils.py` for improved code maintainability.
- Added a new configuration file `config.conf` for Eltex devices to facilitate testing.
- Introduced an expected output JSON file `config.expected.json` to validate the parsing of Eltex configurations against expected results.
- Removed the internal `_decode_utf` method from the `Keenetic` class and replaced its usage with the new `decode_utf` utility function for decoding interface descriptions.
- Added a new configuration file `config.conf` for Keenetic devices to facilitate testing.
- Introduced an expected output JSON file `config.expected.json` to validate the parsing of Keenetic configurations against expected results.
