Plasma 6 proposal: natural scrolling by default (for touchpads only)

About as controversial as double-click... ;)

GNOME, Windows and macOS all use reverse / "natural" scrolling by default for touchpads (macOS goes a step further and does it for mice too; GNOME and Windows do it only for touchpads). I got used to it a long time ago and find "normal" scrolling on touchpads a bit strange now, I think a lot of users switching from other platforms feel the same.

A major downside right now is that natural scrolling has a few quirks / annoyances, most notably that it doesn't work for horizontal UI elements, like tabs. They go the opposite of how you move your fingers, breaking the whole direct manipulation / scroll the content not the view / "natural" element. This happens in both GTK and Qt apps and should probably be fixed.