DOMMatrix: throw SyntaxError for relative units in sign()

MayHaveRelativeUnit() only looked at the root node, so transforms with
hidden relative units—e.g.
  • scale(sign(1em))
  • translateX(calc(10px * sign(1em - 10px)))
  • rotate(calc(5deg * sign(10%)))
were accepted. Make the hook virtual and recurse through NumericLiteral
and Operation; CSSMathFunctionValue now forwards to it.

DOMMatrix-001 passes; drop its failure expectation.

Bug: 416080505
Change-Id: I51b36a282e958acaa499f3314be28925517d3111
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6733217
Reviewed-by: Jinho Bang <zino@chromium.org>
Commit-Queue: Jinho Bang <zino@chromium.org>
Reviewed-by: Daniil Sakhapov <sakhapov@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1487493}