Server Fetch mode

This is a tracker for https://github.com/nodejs/node/pull/65139, which introduces the Fetch model used by Hono and other frameworks. We should probably follow this as the future direction for HTTP in Node.js. I’ve already done some research into a model we could follow, and hopefully I can consolidate it soon and share the document with you.

Start by reading Node.js pull request #65139 and the existing research mentioned in the discussion. Identify the proposed Fetch model and how it could guide HTTP work in Express; done means consolidating the findings into a design document and sharing it for discussion.

Written by the indexing model from the issue text.