[css-color] Tests assume old hsl()/hsla() clipping behavior or depend on unclear gamut mapping to sRGB

[weinig]

https://github.com/web-platform-tests/wpt/issues/45814

Removes tests that were assuming the CSS Color 3 rules for hsl()/hsla() where lightness and saturation values outside of 0-100 were clamped to that range. CSS Color 4 states that only saturation below 0 is clamped.

To make it clear that only the saturation clamping is being tested, the tests where that is still tested have been renamed to be more clear.