Add support for polars (perhaps via narwhals)

[david-waterworth]

Is your feature request related to a problem? Please describe.
I've mostly migrated my python analytics workflow from pandas to polars. This means in order to use a lot of great libraries such as aws-sdk-pandas I need to convert between polars and pandas

Describe the solution you'd like
aws-sdk-pandas seems like a great candidate for migration to being dataframe agnostic, i.e. by internally using narwhals as a dataframe agnostic api.

An alternative might be to refactor methods that accept dataset=True to instead take a string (i.e. dataset="pandas" or dataset="polars").

[jaidisido]

Thanks @david-waterworth, we have considered other data frame formats such as polars in the past but have found that there is very little uptake compared to pandas for us to justify the dev effort that would be required to include them. We will keep on eye this however and might reconsider in the future