Enhancements: Code Refactoring and Additional Test Files

[yihong1120]

Dear Developers,

I hope this message finds you well. I have recently undertaken an initiative to refactor the codebase of your YOLOv8 implementation and added comprehensive test files to augment the existing setup. This effort was aimed at improving the overall maintainability and reliability of the code.

My modifications include reorganising the existing code for better clarity and efficiency. Furthermore, I have diligently crafted test cases for the newly added modules, following the principles of unit testing, to ensure robustness and fault tolerance.

The test files primarily cover the various functionalities in the utils and main modules. For instance, they include tests for the Trainer and Tester classes, along with other utility functions, ensuring their correct behaviour under various scenarios. These tests use mock objects to simulate different environments and isolate the functions under test, which helps in verifying their integration and effectiveness.

In addition to these changes, I have submitted a pull request detailing my contributions. It would be an honour to have my alterations considered for integration into the main project. I firmly believe these enhancements can substantially benefit the project, streamlining future development and testing phases.

Thank you for your time and consideration. I am eager to hear your thoughts and feedback on this undertaking.

Best regards,
yihong1120