fix(ext/node): don't use user manipulated Response objects, use correct `rawHeaders` structure#29105

Fixes https://github.com/denoland/deno/issues/28022 Previously, when a user manipulated the global `Response` object, we would use that object when passing the response from the Node shim to `Deno.serve`. This caused issues when the user manipulated the `Response` object in a way that would break `Deno.serve`. The raw headers bug is that we were exposing the `rawHeaders` field on `Incoming` as a `Headers` object, instead it's supposed to be a flat array of the header keys + values. I.e. `["Content-Type:", "application/json", "Host:", "http://localhost"]`