b847cc0426
This draws a highlight line on the active edge of regions, like side bars and toolbars, while dragging to resize them. Similar as we do for area resizing. This has marginal utility while using a mouse, but is much more important when using a pen. More so when the pen has a minimum pressure for clicking. Even more so when using touch as your finger covers the hit target. Pull Request: https://projects.blender.org/blender/blender/pulls/136337