Using "OS name" is clearer than "Base system" when we want
to check what's the current OS/distribution combination is.
Fix that by renaming the label.
https://bugzilla.gnome.org/show_bug.cgi?id=770593
Having the OS name and architecture at the same place proved
to be harder to understand than having the processor arch.
Fix that by splitting the OS name and type labels in different
rows.
https://bugzilla.gnome.org/show_bug.cgi?id=770593