Support for Positron IDE

[GitHunter0]

Please describe your feature request

Following discussion posit-dev/positron#5082 , it would be very good to have box modules import working in Positron IDE.

For example, consider the case below.

We have module1.R, module2.R and __initi__.R files, all in directory C:/project/modules/, with C:/project/ being our R working directory.

# module1.R
f1 <- function(x) return(x)

Running box::use(./module1[f1]) interactively from module2.R should work.

It currently works in RStudio but still not in Positron.