This moves to predominantly supporting only lazy dataframes for most
operations. It removes a lot of the type conversion between lazy and
eager dataframes based on what was inputted into the command.
For the most part the changes will mean:
* You will need to run `polars collect` after performing operations
* The into-lazy command has been removed as it is redundant.
* When opening files a lazy frame will be outputted by default if the
reader supports lazy frames
A list of individual command changes can be found
[here](https://hackmd.io/@nucore/Bk-3V-hW0)
---------
Co-authored-by: Ian Manske <ian.manske@pm.me>
# Description
I would like to help with `polars` plugin development and add tests to
all the `polars` command's existing params.
Since I have never written any lines of Rust, even though the task of
creating tests is relatively simple, I would like to ask for feedback to
ensure I did everything correctly here.
# Description
This is just some cleanup. I moved to_pipeline_data and to_cache_value
to the CustomValueSupport trait, where I should've put them to begin
with.
Co-authored-by: Jack Wright <jack.wright@disqo.com>
