Add file_edit to tidyview

[crew102]

As discussed in tidyverse/reprex#204 (comment)

Which function do you think the default file_edit() handler should call - utils::file.edit() or the version that RStudio defines in the global environment? I would lean towards using RStudio's version, due to the fact that the fix introduced for rstudio/rstudio#3475 won't be available in most people's current version of RStudio.