afd760f2b7
Some mice have an additional horizontal scroll wheel. This patch adds support for receiving such events. By default it is used to scroll 2D editors left and right. I originally developed this because I was missing it in the spreadsheet, but it seems to be useful in many other editors too. It's supported on Linux (Wayland), Windows and macos. Pull Request: https://projects.blender.org/blender/blender/pulls/138758