Modifies the screen edge button and panel size button in the panel edit mode to make them easier to understand and look better (as suggested in this Phabricator task: https://phabricator.kde.org/T10047):
- When you hover over the screen edge button it now shows a move cursor (SizeAllCursor)
- The screen edge button now has an icon (transform-move)
- The panel size button now has an icon (resizecol/resizerow)
{F6455141}