Normalize scrolling speed for touch pad

At the moment, scrolling speed for classic mouse is quite good. For each wheel scroll, you scroll one tab.

However, users of touch pads or Magic Mouse experience super fast scrolling. It is difficult to use the scrolling behaviour for them. Because of that, we need some kind of solution to normalize scrolling speed.

The problem derives from multiple wheel events fired whenever the touchpad is used.

Start by locating the wheel-event handling in the repository and reproduce scrolling with a touchpad or Magic Mouse. Compare it with classic mouse behavior, then verify that touchpad input no longer advances through tabs excessively while preserving the existing one-tab-per-wheel-scroll behavior.

Written by the indexing model from the issue text.