Add video segmentation feature

[HendricksJudy]

Add video segmentation functionality to the project.

• segment_anything/predictor.py

  • Add segment_video function to read video frames and segment objects using SamPredictor.
  • Import cv2 for video processing.

• demo/src/App.tsx

  • Add state variable isVideo to handle video input.
  • Add handleVideoUpload function to process video files and call segment_video.
  • Update runONNX function to handle video frames if isVideo is true.

• demo/src/components/Tool.tsx

  • Add isVideo prop to handle video input.
  • Update render method to display video frames if isVideo is true.

• README.md

  • Add instructions for using the new video segmentation feature.