Update notebooks to use FieldDataset, patchify

[alvinzz]

No description provided.

[9q9q]

thanks Alvin! just aesthetic nits about the vanilla tutorial notebook:

1. for some reason the plots/figures all look undertrained, could you return them to original condition? everything should look the same as before if you run it without changing params.
2. not sure why this is happening, but the tutorial Field images have different vranges than they should. i set it so the contrast is higher: https://github.com/rctn/sparsecoding/blob/main/tutorials/vanilla/src/utils.py#L64, but it doesn't look like that is being applied to notebook in this branch
3. could you fix the warnings? if it's a jupyter version/package issue i can do it