Add an Any white point

[Ogeon]

This adds white_point::Any, which represents an unspecified white point. That makes it possible to remove a number of white point type parameters where they didn't matter or weren't used, other than to fill a hole in Xyz or Yxy types. This simplifies a lot of traits, removes ambiguity and presumably also reduces the amount of generated code.

Closed Issues

• Closes Add an "anything" white point for agnostic CIE spaces #194

Breaking Change

• Some places that would receive or return specific Xyz or Yxy types have been changed to use the Any white point. It's easy to cast between white points with the new with_white_point method.
• WhitePoint and Primaries have been changed to be parametric over the number type, changing them toWhitePoint<T> and Primaries<T>.
• RgbSpace, RgbStandard and LumaStandard have also been changed to RgbSpace<T>, RgbStandard<T> and LumaStandard<T> to be able to pass the type parameter on to WhitePoint and Primaries. Removing the trait bounds from the associated types would instead have required trait bounds in impls.

[github-actions]

Benchmark for ae7647a

Click to view benchmark

Test	PR Benchmark	Master Benchmark	%
Cie family/lab to lch	3.2±0.17µs	3.1±0.18µs	+3.23%
Cie family/lab to xyz	907.4±53.26ns	870.6±55.41ns	+4.23%
Cie family/lch to lab	2.8±0.15µs	2.8±0.09µs	0.00%
Cie family/linsrgb to xyz	3.9±0.21µs	3.6±0.20µs	+8.33%
Cie family/xyz to lab	9.8±0.53µs	9.9±0.59µs	-1.01%
Cie family/xyz to yxy	670.9±34.92ns	689.6±40.27ns	-2.71%
Cie family/yxy to xyz	672.8±38.16ns	641.9±45.65ns	+4.81%
Matrix functions/matrix_inverse	13.2±0.87ns	13.3±0.82ns	-0.75%
Matrix functions/multiply_3x3	11.0±0.77ns	11.6±0.50ns	-5.17%
Matrix functions/multiply_rgb_to_xyz	4.5±0.26ns	4.6±0.24ns	-2.17%
Matrix functions/multiply_xyz	4.5±0.25ns	4.6±0.32ns	-2.17%
Matrix functions/multiply_xyz_to_rgb	4.6±0.28ns	4.4±0.33ns	+4.55%
Matrix functions/rgb_to_xyz_matrix	24.6±1.54ns	24.1±1.13ns	+2.07%
Rgb family/hsl to hsv	758.3±39.01ns	818.1±80.57ns	-7.31%
Rgb family/hsl to linear hsl	9.8±0.61µs	9.7±0.69µs	+1.03%
Rgb family/hsl to rgb	2.3±0.19µs	2.4±0.19µs	-4.17%
Rgb family/hsv to hsl	1115.4±73.08ns	1231.4±106.85ns	-9.42%
Rgb family/hsv to hwb	283.9±28.62ns	290.0±23.94ns	-2.10%
Rgb family/hsv to linear hsv	9.0±0.69µs	9.2±0.59µs	-2.17%
Rgb family/hsv to rgb	2.2±0.13µs	2.4±0.15µs	-8.33%
Rgb family/hwb to hsv	633.8±42.69ns	661.4±42.56ns	-4.17%
Rgb family/hwb to linear hwb	10.7±0.77µs	10.4±0.60µs	+2.88%
Rgb family/linear hsl to hsl	9.9±0.75µs	9.7±0.51µs	+2.06%
Rgb family/linear hsv to hsv	9.3±0.50µs	9.4±0.35µs	-1.06%
Rgb family/linear hwb to hwb	11.5±1.24µs	10.6±0.60µs	+8.49%
Rgb family/linsrgb to rgb	4.8±0.33µs	4.9±0.50µs	-2.04%
Rgb family/linsrgb_f32 to rgb_u8	6.5±0.47µs	6.4±0.28µs	+1.56%
Rgb family/rgb to hsl	933.4±58.98ns	925.0±65.75ns	+0.91%
Rgb family/rgb to hsv	694.6±110.80ns	706.9±33.23ns	-1.74%
Rgb family/rgb to linsrgb	5.2±0.31µs	5.3±0.38µs	-1.89%
Rgb family/rgb_u8 to linsrgb_f32	5.7±0.37µs	5.6±0.37µs	+1.79%
Rgb family/xyz to linsrgb	7.0±0.48µs	7.2±0.39µs	-2.78%

[Ogeon]

bors r+

[bors]

Build succeeded:

• ci