Suggestion for preferences lists buttons style update

[joshas]

There are a few lists in preferences with control buttons: add, remove, edit, move up, move down. As they are using deprecated stock items, it would be a great time to update them.
After looking how modern GTK3 programs are implementing buttons below lists, I found some examples.
GNOME Text Editor (gedit) is using icons for add and remove:

GNOME Files has ordering buttons (move up, move down) with arrow icons:

Would similar solution be good enough for Sunflower, or should we include additional text labels? Are icons on buttons necessary when we already have text labels?

[MeanEYE]

Whole preferences window needs to be redesigned. I didn't even touch it yet. Am leaving it as is on purpose until I decide upon a uniform structure and looks. What you have linked looks good and I planned on having similar layout but I want to get main window up and working properly before I dedicate myself to preferences as they are not really something people look at all the time.