Update license line in Python files

[UltralyticsAssistant]

This pull request updates or adds the license line to the beginning of each Python file.

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

This pull request adds licensing information to various files in the Ultralytics/Velocity project.

📊 Key Changes

• Added license headers to several Python files (plots.py, utils/KLT.py, utils/MSV.py, utils/NLS.py, utils/common.py, utils/images.py, utils/strings.py, utils/transforms.py, utils/vid2images.py, vidExample.py) and the GitHub Actions workflow file (format.yml).

🎯 Purpose & Impact

• Compliance: Ensures all files display the appropriate licensing information for clearer legal compliance and transparency.
• Consistency: Maintains consistent project documentation, aiding both developers and users in understanding the licensing terms.
• Community Trust: Reinforces trust in the project by making the licensing explicit and easily visible across the codebase.