Add up, show_preview, and sort actions to toolbar
They are also present in kio open/save dialogs.
This is intended to stir up some discussions about toolbar defaults for dolphin.
I was wondering whether I should also add show hidden files and whether sort is really necessary/useful. If not, we should also consider removing it from kio open/save dialogs.
I have now also joined the KDE File Management matrix channel if you prefer discussions there.