Add a second zoom button (a.k.a. Youtuber Zoom)

[EnnuiL]

What? Did you think we never had this in mind? We can always do this! We just like being perfect :p

While we can half-arse a limited button with fewer options than the main one? We don't want that! We aren't vultures! So first, we'll prioritize getting everything else right (including zooming itself, configuration, and so on) and then we can pull off something great