Fix bug in JSON type cast

[vominhmanh]

This exception occurs in type cast when casting json.

Unhandled Exception: type '_Map<Object?, Object?>' is not a subtype of type 'Map<String, dynamic>?'

🛠️ PR Summary

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🌟 Summary

Improved data parsing in the YOLO Flutter app for better performance and reliability.

📊 Key Changes

• Simplified the process of converting JSON to ClassificationResult objects by directly casting JSON maps, removing intermediate steps.
• Eliminated unnecessary null checks in the parsing logic to streamline code.

🎯 Purpose & Impact

• Purpose: The main aim is to enhance the efficiency and accuracy of the data parsing from JSON to object models within the app. This is achieved by reducing the complexity of the conversion process and minimizing potential errors through direct casting.
• Impact: Users can expect a more reliable and slightly faster app performance when it comes to displaying object detection results. This update paves the way for smoother app interactions and contributes to the overall robustness of the system. Developers will find the codebase cleaner and easier to maintain or extend. 🚀🔧

[github-actions]

CLA Assistant Lite bot All Contributors have signed the CLA. ✅

[vominhmanh]

I have read the CLA Document and I sign the CLA

[glenn-jocher]

@vominhmanh PR merged! Thank you for your contributions and please let us know if you spot any other issues :)