build a decentralized age detector from webcam images

[martinjaggi]

as an example use-case, let's build a decentralized model for browser-based images

we can start from a stand-alone-version based on https://github.com/justadudewhohacks/face-api.js/ (uses TF.js) see for example https://www.codeproject.com/Articles/5276827/AI-Age-Estimation-in-the-Browser-using-face-api-an

on top of it, we only need to extract gradients, to incorporate it into collaborative DeAI training. will also be a good use-case to refine our task-descriptions and image preprocessing pipelines and UI