Implement hysteresis for inference computation

[peddybeats]

• We should add a inference state variable
• Each inference made, should update that variable by max(epsilon, | new - old | ) in the correct direction
• Be disciplined about how we return 0s vs errors vs undefineds ex

[Berkmann18]

One thing to bear in mind is that the inference text is being repainted every single frame (even when the inference state is set to "Off").
This can be observed by going on a browser's devtool by either:

• enabling paint flashing and then one should see at least 2 green boxes (representing repainted areas on the page)
• navigating to the container Element such that the camera view and inference text elements are shown, what could be observed is a constant change of at least 2-3 HTML elements.

@misterpeddy I suppose (judging by the fact this issue is "In progress") you are working on this?