This exposes an existing issue with interpolation where it is not clear
in what situations zero-valued dimensions should be excluded from the
interpolated value of a dimension-percentage mix (e.g. `calc(50% + 0px)`
vs `50%`) - but this is just a serialization issue as both
representations are resolved to the same used value
This also required supporting composition for it's constituent types
(`RadialSizeStyleValue` and `BorderRadiusRect`).
The remaining failing subtests in the two affected tests are because we
dont yet support compositing of mixed values
Some subtests changed in response to this CSSWG resolution:
https://github.com/w3c/csswg-drafts/issues/11494#issuecomment-2675800489
Basically, `border-style: none` now affects the used value of
`border-width`, not the computed value. (And the same for `outline`
properties.)
This affects way more tests than I expected because
interpolation-testcommon.js now adds tests for composition.
Fixes a crash on https://www.lego.com/en-gb/product/game-boy-72046 :^)
The apparent regressions in clip-path-interpolation-xywh-rect.html are
because of false positives. Something about the test was causing it to
compare two wrong values that happened to be the same. Now one of the
values is correct, they don't match.
