fix(wayland): workaround scrollbar reappearing when set to 'hidden' and scrolling using the touchpad
On Wayland, sometimes the scrollbar reappears on the left side of the screen even when the scrollbar is set to 'hidden'.
- This happens when scrolling twice using the touchpad.
- This only happens on Wayland
- This only happens with Qt 5.14 or newer
This patch is a workaround for a change in Qt 5.14. Due to "scroll phases", scrollbars get set to visible when starting to scroll, and don't hide themselves afterwards.
Note: this is a copy of MR !94 (closed), since I accidently created the merge request on the master branch, which makes GitLab fail rebasing since master is protected.