Initial implementation of polars plugin

[areleu]

• fixes Add Polars plugin #1662

Making the PR to see if I am overseeing some validations.

Caveats

• Polars does not allow mixing tz-aware and naive datetimes, one of the pandas tests contains this kind of mixed input, so there will be a difference in the behaviour there.
• Polars does not automatically parse objects when reading, we could implement a parser but IDK how good of an idea it is, the only use case I see is for geojson but polars have limited support for geo data.