Refactoring cleanup

[glenn-jocher]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Refinements and clarifications in argument descriptions and labels across multiple scripts including detect.py, test.py, and train.py.

📊 Key Changes

• Improved argument documentation in detect.py, making the help messages more consistent.
• Extensive updates to test.py including clearer argument help messages and re-ordering of code for readability.
• Changed the help message for the --data argument in train.py to maintain consistency across scripts.

🎯 Purpose & Impact

• These changes aim to make the code more understandable and user-friendly for developers and users by providing clearer explanations for command line arguments.
• While these updates are minor, they contribute to a better user experience and could ease the learning curve for new users working with the YOLOv5 codebase. 🧑‍💻📈
• There is no direct functional impact on the models or inference, so users should not experience any changes in model performance or behavior. 🚀📊

[glenn-jocher]

/rebase