Improve navigation above `/home` for `selectDirectory()`

[matiasandina]

Currently, if the user wants to go to:

/media/usr/whatever_sd

They have to click the 3 dots and write the path manually (or at least /media or / and navigate). Would it be possible to have a better GUI navigation experience with this? It throws the user to think that they actually don't have access to /media

[hutch3232]

This sounds like this feature request I made that sadly was closed due to inactivity
rstudio/rstudio#11926