Provide a "low contrast flash" mode

[sapphire-arches]

We can't change the intensity of flashing in the upper section (play/record/etc.) as those LEDs are only on or off, but we could audit how we use high-contrast flashes on the pad grid.

This include:

• Active clip flashing in grid view

[Metamere]

With my recently merged PR, I managed to reduce the contrast when larger pads are pressed in the kit velocity keyboard view. I tried to make it so that the overall brightness change is more consistent. If you change a drum pad brightness by XX%, that will have a bigger overall effect when the pad covers the whole screen. It was way too much of a strobe effect at first, but I think the current version is pretty pleasant to use, and is still useable when you turn down your system brightness. Please give it a try and let me know what you think.