Implement Unit Tests for Config Module

[H4ppy-04]

**Description: ** Add unit tests to ensure the functionality of the Config module is working as expected.

• Write unit tests for the config module in the Config directory
• Ensure the check_config_validity.py script runs without error and is properly validating the config
• Write test cases to verify that the formatter module in the Config directory formats the output correctly
• Verify that the logger.ini file in the Config directory is properly configured
• Add the unit label to this issue
• Implement testing project structure #40