Code Insights: [FE] Show shutters elements only if container has a scroll

Created by: vovakulikov

Prior to this PR, we had a problem with the scroll box at the legend block layout. We always showed a scroll bar even if visually legend block didn't have overflowed content. With this PR's change, we calculate scroll height and client height to determine whether a legend block has overflowed content or not, and based on this calculation render or not shutter scroll box elements.