Test Polars compatibility and performance

[toni-neurosc]

So Polars is a replacement for Pandas written in Rust (https://pola.rs/) which can be 10-100x faster than Pandas depending on the operations. However, it's still not fully compatible with certain things, for example, I have read that it can have problems working directly with scikit-learn.

PyNM is using Pandas dataframes to store analysis results, so I think at some we should at least give Polars a go and see if it would fit the project.

Demo of Plotly Dash with Polars https://www.youtube.com/watch?v=_iebrqafOuM