Scroll wheel on speed icon to change speed

**Is your feature request related to a usage problem (not a bug)? Please describe.**
I am used to using Enhancer for Youtube, and on that I can use the scroll wheel while pointing at the speed icon to change the speed. I find it super convenient when my hands are not on the keyboard, especially when I'm not quite sure what speed I want yet.

**Describe the solution you'd like to see implemented**
When the mouse hovers over the speed icon, using the scroll wheel will increase or decrease the speed by one step per... scroll wheel clicky thing. (The step size is already mentioned in other issues so I will not repeat here.)

**Describe alternatives you've considered**
There are plenty of alternatives that use the keyboard, and there are already issues for those.

**Screenshots**
None.

**Additional context**
No extra notes.