Checkmk Werk 13920: UI: Increase width of scrollbars

ID: 13920 Title: UI: Increase width of scrollbars Component: Multisite Level: 1 Class: Bug fix Version: 2.2.0i1 The width of UI scrollbars was rather small, making it difficult to hit the scrollbar with the cursor. The scrollbar width is now increased and in the dark theme its color is made lighter for a better user experience.