feat(io): add MMPose I/O support (#175)

[RahulBera15]

This PR adds support for loading pose estimation outputs generated by MMPose.

Features:

• Implements from_mmpose_file loader
• Parses frame_id, keypoints, and keypoint_scores
• Supports single-frame and multi-frame JSON formats
• Handles missing tracking IDs
• Adds JSON schema validation for MMPose JSON files
• Includes tests and example script

Closes #175

I would appreciate feedback from the maintainers.

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[RahulBera15]

Hi ,
I’ve implemented MMPose I/O support and opened a pull request for this issue.
PR: #870

The implementation includes the loader, validation schema, tests, and an example script.
Please let me know if any changes or improvements are needed.

Thanks!