convert some polars benchmarks to atime

[tdhock]

https://pola.rs/posts/benchmarks/
code is in python https://github.com/pola-rs/polars-benchmark/tree/main/queries/polars
would need to translate to library(polars) in R
recommended install https://pola-rs.github.io/r-polars/index.html#install