scvi-hub enhancements

[watiss]

See this PR for more context

• [x] Account for data/model prefixes -> we chose not to do this to keep naming cohesive across the board (+ given that we control both saving and loading from this api)
• [x] Do we need to use a different name than "Large data"?
• [x] There might be a more efficient way of reading the latent property from adata that doesn't require reading the file. Note that this would only matter for datasets with large metadata (obs/obsm/etc.) since .X is anyways backed on disk. So for most datasets this would bring a marginal improvement.
• [x] Consider using an enum or named tuple for constants
• [x] functools.cached_property might help cleaning up some code -> since I evaluate the None-ness of those attributes (see eval_obj) inside __repr__, I think I would prefer to avoid using cached_property in this case.
• [ ] Can we make a hf space to help query hf?
• [ ] Make an issue in huggingface_hub to provide an API for retrieving a pandas DataFrame of all ModelInfo's, rather than lose string representations.