Lerp HSVColor and HSLColor hue along the shortest arc (#191186)

Hue is an angle but we lerped it like a plain number so anything
crossing 0 took the long way round. 300 to 60 should be a 120 hop
through red (it was doing 240 through cyan)

Added a `_lerpHue` helper that folds the delta into (-180, 180] first
(used by both lerps)

Heads up - 0 -> 360 doesn't sweep the wheel anymore since its the same
angle. Two tests relied on that so I moved them to 0 -> 180

fixes #138301 

_(I used antigravity to help with that fix) and I went over the
checklist_

<img width="640" height="290" alt="hue-lerp"
src="https://github.com/user-attachments/assets/9b28ab69-886f-48e6-bec7-e4989d4d1b11"
/>