Update ESM hook for consolidated node API

[cspotcode]

nodejs/node#37468 consolidates the loader hooks to only 2x functions. If/when it lands, we'll need to export implementations of those functions. We should be able to implement them largely on top of what we already have. The default* functions we get from node will be different, though.

Updated node docs are here: https://github.com/nodejs/node/blob/master/doc/api/esm.md#loaders