[chore] Port remaining tests to the new testsuite

[LeaVerou]

This is a master issue to track the different issues around porting old tests to the new JS-first format:

• [chore] Port Parsing tests to the new test format #393
• [chore] Port missing Constructor tests #394
• [chore] Port Color modification tests to the new test format #395
• [chore] Port Contrast tests to the new test format #396
• [chore] Port missing Chromatic adaptation tests #397
• [chore] Port Matrix multiplication tests to the new test format #398

For whomever is interested in tackling it, I would recommend using some kind of AI tool like GitHub Copilot and just checking that the results are correct — it's way easier than doing the tedious work of porting them manually.