Add MediaPipeBodySegmentation implementation to video filter in the demo

[ltrung]

Description of changes: Add MediaPipeBodySegmentation implementation to video filters in the demo. There are three options:

• Beach background image
• Blue background color
• Blur

For more information, please refer to https://github.com/tensorflow/tfjs-models/blob/master/body-segmentation/README.md

This is to replace the now deprecated option Body-Pix that is previously available in the demo under Segmentation option.

Testing:

Can these tested using a demo application? Please provide reproducible step-by-step instructions.

• Join meeting in demo
• Toggle any of the new three video filter MediaPipeBodySegmentation - (Beach) | (Blue) | (Blur)
• Verify that the desired effect is applied.

Checklist:

1. Have you successfully run npm run build:release locally? Yes

2. Do you add, modify, or delete public API definitions? If yes, has that been reviewed and approved? No

3. Do you change the wire protocol, e.g. the request method? If yes, has that been reviewed and approved? No

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.