Go back to our machinery for Recent files instead of reading recent:/// as-is

Go back to our machinery for Recent files instead of reading recent:/// as-is

Reading recent:/// as-is is probably fine for OPEN mode.  But for SAVE mode, we want to present
a list of recent directories.  So, we go back to our old machinery for now; in the future
we'll probably just use recent:/// and extract the list of recent directories from there.

This also fixes showing the Recent item as highlighted when the file chooser starts up.

Signed-off-by: Federico Mena Quintero <federico@gnome.org>