Put media features as part of Custom Data Contribution

New media features are being added, such as https://developer.mozilla.org/en-US/docs/Web/CSS/@media/aspect-ratio

By generalizing this part of support, we can support new media features in the future without having to change code: https://developer.mozilla.org/en-US/docs/Web/CSS/Media_Queries/Using_media_queries#Media_features

@aeschli What do you think?