should we use polars in sourmash to read manifests and picklists?

Seems like "maybe"? :) Should result in a large speedup.

The biggest problem for me is that our biggest CSV files that are routinely encountered tend to be in zip files, which per https://github.com/pola-rs/polars/issues/9601, cannot be nicely loaded with polars. Can we use parquet files instead?
