scrollbar resizer should show second arrow on each side of the bar itself to better represent the function.
ideally also the arrows on the bar itself would be operable.

meaning, the bar itself (the block that is in the middle) shows arrows at both sides upon mouseover. but it would make it easier to understand that those arrows themselves are also operable if there was a second set of arrows on the bar itself, pointing to the middle of it.

this is a followup report of ZBX-227 as discussed.
that issue was first commented on as being duplicate of DEV-85 - which i can't access.
then it was closed as wontfix, without further explanations.