Add `Color::as_lcha`

[LiamGallagher737]

Problem

Other color spaces have a as_xxx with returns a Color and a as_xxx_f32 that returns a [f32; 4], the lch color space only has a as_lch_f32 that returns a [f32; 4].

Solution

Add a new method, as_lcha, for bevy_render::Color for converting any Color type into a Color::Lcha variant.

Note

Alongside this it would also make sense to rename as_lch_f32 to as_lcha_f32 as it also returns the alpha, not really big enough for its own issue.

[iwek7]

I can try to do it if it is still free

[LiamGallagher737]

Still free