feat: Pose detection

[robingenz]

Is your feature request related to a problem? Please describe:

The ML Kit Pose Detection API is not yet supported.

Describe the solution you'd like:

Add a Pose Detection plugin.

Describe alternatives you've considered:

Additional context:

[robingenz]

This issue can be sponsored if interested. Please contact us in advance by email and mention the issue. PRs are also welcome.

[abhinavchawla13]

@robingenz, note: I think the API is ready now. Would love to see some progress on this one - especially because this would be a bit different in terms of the input to the plugin, as the use cases using pose detection would more often than not require it to work on a video stream (loaded video or webcam). Considering, all the other plugins are using processImage (besides translate), this would be very helpful!