Add shader support to the NeoVerticalSpriteSheet Blt method

[homerggg]

Describe the solution you'd like Add shader support to the NeoVerticalSpriteSheet Blt method.

Additional context It is possible to add a shader to the Render() method but not to the Blt method. I wanted to change my animation brightness using the prefered method (shader), coupled with a potentiometer to adjust brightness. Upon creation a shader, my first instinct was to use it in the Blt method but it is not currently possible.

[Makuna]

https://github.com/Makuna/NeoPixelBus/issues/442