Add Domparser

[autonome]

• Caniuse groups DOMParser, XMLSerializer and other misc bits into a single feature: https://caniuse.com/xml-serializer
• We already have a feature for XMLSerializer from Adding xml-serializer as a feature #1444

This PR:

• adds DOMParser as a standalone feature
• adds a Parsing and Serialization group with both features

If we merged them, it looks like it wouldn't change baseline, but I prefer this explicit approach over Caniuse's kitchen sink approach because developer searches can match on the API better. For example, the Caniuse feature was at the bottom of their own search results for the API name.