Reduced spacing between scrollbar arrows and groove for one arrow; reduce scrollbar padding slightly
I like the new wider Breeze scrollbar slider style for 5.23. However, with one button arrows enabled for scrollbars, I find that they don't look right and there is a large gap between the top of the groove and the arrow. This makes the scrollbar look like it isn't at an extremity when it is in fact at an extremity.
This merge request reduces this gap between the arrow and the groove (when one button arrow type is enabled). It also very slightly reduces the padding around the slider/groove while keeping the slider the same thickness to make the scrollbars more compact.