Now that we don't remove whitespace when parsing, we don't need to
artificially insert it back in again when serializing. We do now need
to trim leading and trailing whitespace from UnresolvedStyleValues, as
this previously was done as part of the whitespace insertion.
This makes our serialization of UnresolvedStyleValues more correct and
gets us a few WPT passes for each property in the Typed OM tests.
The `transform` property is now parsed based on its JSON data, and
shouldn't behave any differently than before.
This makes `<transform-list>` and `<transform-function>` work in the
`syntax` descriptor for `@property`, and also means we know that
`transform` can accept the `none` keyword. We get a few WPT passes out
of that.
Now we pass all WPT tests in:
`css/css-properties-values-api/at-property-cssom`.
Note: Failing tests were false positives.
Proper handling of inheriting values and detecting computational
independence will be done in another PR.
