Send `Host` header as the first header

The minor issue from https://github.com/node-fetch/node-fetch/issues/1569.

Currently it sends Host header as the last header. (If a user did not add it manually)

I think it should send Host header as the first header like it browsers and other libraries do.

Prepend it instead of appending.

---

"node-fetch": "3.2.3"