Add support for transfer learning

[javierluraschi]

Add a predict block for https://twitter.com/jason_mayes/status/1482243737426153474?s=21, implementation can be based of https://github.com/hal9ai/hal9ai/blob/main/scripts/predict/movenet.txt.js.

This is a bit of a harder task, so definitely reach out at https://discord.gg/jP8W48EVa3 for details.