CSSCompoundDataType (#49186)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/49186

Next up for transforms, and for some future cases, it is convenient to be able to export a single marker type like `CSSTransform`, that can expand to a variant of multiple possible types of different shape (e.g. `CSSMatrix3D` vs `CSSScale`).

It is also best (for code size) to only have a single representation of compound types (e.g. `<CSSLength, CSSPercentage>` generates a separate copy of code compared to `<CSSPercentage, CSSLength>`).

This diff introduces `CSSCompoundDataTypes` which allows composing types, which are then flattened out to discrete types during parsing. For simplicity, `CSSCompoundDataType` cannot currently be nested inside of other `CSSCompoundDataType`, though this could be added in the future.

```
/**
 * Marker for the <length-percentage> data type
 * https://drafts.csswg.org/css-values/#mixed-percentages
 */
using CSSLengthPercentage = CSSCompoundDataType<CSSLength, CSSPercentage>;
```

Changelog: [Internal]

Reviewed By: lenaic

Differential Revision: D69089416

fbshipit-source-id: 8645009f06eb14b1ac4437a4fc4dd6b9ad3f88a2