Pitch bend threshold

[wienski]

My arpeggios with pitch bend enabled often take on lo-fi detuned vibes, which sometimes is cool, but sometimes is really annoying.

I could just get good at playing the striso, but it's not a realistic way to solve this problem :D

I could turn pitch bend off, or lower the sensitivity, but that would be rather limiting.

This PR instead changes the response curve of the x axis to the following: https://www.desmos.com/calculator/2ka73q4kpj

The dead zone half-width was also added as a configuration option, both in configurator and live settings (it's on an E, right after the Y sensitivity knob).

Having tested that for a day, I'm very happy with how it's turned out. With this enabled, I can play in tune, but still use bends and pitch vibrato.

I figured I should share this with the Striso community, and I'm willing to resolve any shortcomings of the implementation if it's not good enough to merge as-is.

[pierstitus]

Thanks for your contribution, sounds like a nice improvement! I've been thinking about sensitivity curves and kept the row above the sensitivity settings empty for curves, so this pitch bend dead zone setting could go on the F4, above the bend sensitivity.

[wienski]

I've relocated the knob to F4 as suggested.