Switch to MoveNet as a default ML model

[ivelin]

Is your feature request related to a problem? Please describe.
We currently use PoseNet 2.0 as our default pose detection model.
However benchmarking has shown that MoveNet performs better:
https://blog.ambianic.ai/2021/09/02/movenet-vs-posenet-person-fall-detection.html

Describe the solution you'd like
Keep PoseNet as an alternative option that can be configured for use, but switch default model to MoveNet.