Bug 1588

When scrolling the pulse view horizontally, it scrolls in the wrong direction (the viewport is scrolled to the left while you scroll to the right on your device). This is especially noticeable, when using a device, that can natively scroll horizontally, like a touchpad or a pointing stick

Steps to reproduce:
- start pulseview and open a captured trace or capture a new one.
- zoom in enough so you can scroll horizontally
- try to scroll towards the end of the captured trace by either of the following
   - hold <Alt> and scroll down* (some accessibility functions might interfere with this guesture, so disable that first)
   - hold <middle pointing stick button> and push the pointing stick to the right*
   - swipe with two fingers (or with one finger on the bottom edge) to the right* on the touchpad
* if you have something like "natural scrolling" enabled for this device, move in the opposite direction

Expected behaviour:
- the pulseview scrolls towards the end of the captured trace

Actual behaviour:
- the pulseview scrolls towards the beginning of the beginning of the captured trace

Hardware:
- any pointing device that can scroll horizontally (or an ordinary vertical scroll wheel + <Alt>

Software:
- pulseview 0.4.1 and 0.4.2 and current nightly on Xubuntu 20.04 and OpenSuse Leap 15.1