Read hsl() hues that have a CSS angle unit - #543

Thanks, I confirmed the bug on main: hsl(120deg, 100%, 50%) raises ValueError: bad hue argument value '120deg', and the same for turn and grad. Converting the hue to degrees before calling cssParse() is the right fix, and the conversion factors and the :g formatting look correct to me.

The new test fails in CI, though, so the PR can't merge as it stands. Four of its cases use the space-separated syntax (hsl(120deg 100% 50%), HSL(120DEG 100% 50%), hsl(0.5turn 100% 50%), hsl(200grad 100% 50%)), and ReportLab's cssParse() doesn't accept that syntax at all, with or without a unit: even hsl(120 100% 50%) raises css color ... has wrong number of components. The comma-separated cases are fine. The description says the space-separated forms work, which isn't the case.

Please remove the space-separated cases from the test and from the description, and keep the comma-separated ones. Supporting the space-separated (and / alpha) syntax would be a separate change, and I'd rather not include it here.

The branch also conflicts with main now, in CHANGELOG.md (and maybe in tests/public_api.json). Please merge main into the branch and keep all of the existing entries.

Thanks for checking. I removed the space-separated cases from the test and kept the comma-separated ones, merged main into the branch, and updated the description. pytest, ruff and mypy pass.

convertColor() now converts such a hue to degrees before calling cssParse(), so hsl(120deg, 100%, 50%), hsl(0.5turn, 100%, 50%), hsl(200grad, 100%, 50%) and hsla(240deg, 100%, 50%, 0.5) give the expected colors. A hue without a unit is unchanged. cssParse() doesn't read the space-separated syntax at all, so that's left for a separate change.