Option to make ScrollbarHandle lay on top of all other marks when scrolling?

[phongvcao]

I think it would make more sense that the ScrollbarHandle stays on top of the marks (highest priority compared to marks) as opposed to the current config that the ScrollbarHandle gets overlaid by marks.

The reason is lots of people (including me) already have a left SignColumn enabled and hence with ALE / coc.nvim we can already see what errors are exactly at which line in the current view of the file. Hence even if ScrollbarHandle lays on top of the marks (a.k.a. having higher priority than the marks) we still know the errors/lints/search/etc. positions in the current view using the left SignColumn.