Update TryExcept(msg='...')`

[glenn-jocher]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Improvement to error handling messages in Ultralytics YOLOv5.

📊 Key Changes

• Removed default error message content, leaving an empty string.
• Adjusted error and warning message formatting to include a space after custom message prefix.
• TryExcept decorator and context manager updated to enhance clarity of error messages.

🎯 Purpose & Impact

• These changes ensure error and warning messages are more readable and less confusing for users.
• Developers can now supply more concise custom messages without a redundant default message getting in the way.
• 🚀 For users, this means clearer understanding of what went wrong, leading to easier troubleshooting and debugging.