Ensure output of Normalize is bounded between zero and one

[bruno-f-cruz]

Fixes #1399 .

The current version of Normalize implements ConvertScale with shift in "raw", unscaled, units.

https://github.com/bonsai-rx/bonsai/blob/404b092b501fbd9a0db5ccce76bf695623e6ba7c/Bonsai.Vision/Normalize.cs#LL34C17-L34C32

                var range = max - min;
                var scale = range > 0 ? 1.0 / range : 0;
                var shift = range > 0 ? -min : 0;
                CV.ConvertScale(input, output, scale, shift);

However, the native function from opencv seems to follow algebraic order of operations (i.e. Multiplication -> Addition), resulting in applying the scaling first and the shift second.

It seems the easiest way to correct this would be to normalize the shift by the range:

var shift = range > 0 ? -min*scale : 0;