Remove missing values in a `fc_filter()`

[pasahe]

Add a new argument called na.rm in the fc_filter() function. With this new argument, users could specify whether or not to remove missing values when a filter contains missing values. The default will be TRUE to mimic the current behaviour.

For instance, in the following example fc_filter() removes missing values automatically:

data.frame(XX = c(1,2,NA, 3:9, NA)) |>
 as_fc() |> 
fc_filter(XX >= 5) |> 
fc_draw()

To keep them, the current workaround is to:

data.frame(XX = c(1,2,NA, 3:9, NA)) |>
 as_fc() |> 
fc_filter(XX >= 5 | is.na(XX)) |> 
fc_draw()

The future na.rm argument would allow to keep missings by just specifying fc_filter(XX >= 5, na.rm = FALSE).

[KennethATaylor]

@pasahe Hello from my other GH account! 🙃

Given that the package is meant to follow along with typical tidyverse style/expectations, I wonder if it makes the most sense to do the following instead:

1. Leave the current functionality for fc_filter() (to treat NA values like FALSE) so that the fc_filter() function stays consistent with the behavior of dplyr::filter()
2. Instead, add an fc_filter_out() function that would work similar to the dplyr::filter_out() function that got added in dplyr v1.2.0?