Move JsxDOM types etc. into @rescript/react(-dom)

Proposal:

• Remove modules Dom, Dom_storage, Dom_storage2 from the @rescript/runtime package
• Instead of those, vendor the base package of experimental-webapi
• Make the vendored @rescript/react depend on that
• Split off @rescript/react-dom
• Move JsxDOM/JsxDOMStyle/JsxEvent into @rescript/react-dom
• Make everything work 🙂
• Also make it work/test with rescript-react-native and a with non-React JSX runtime like Xote

Note that any vendoring here (@rescript/react, @rescript/react-dom, relevant parts of webapi and rescript-react-native/Xote) does not mean moving the source of truth for these packages into the compiler repo. It's just for easier and quicker iteration while moving things around.

Once the new shape has crystallized, things need to be synced back to the respective repos.