feat: introduce fetch_hyper (#437)

Extracting hyper-related APIs into separate crate. These APIs should be
treated only as an internal implementation detail of hyper transport and
will never be used directly nor exposed publicly from fetch.

Public APIs are kept to a minimum:

<img width="2327" height="1215" alt="image"
src="https://github.com/user-attachments/assets/de6b0112-5bf0-41bb-95d1-48082e59eeba"
/>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: martintmk

CHANGELOG.md

@@ -12,6 +12,7 @@ Please see each crate's change log below:
 - [`data_privacy`](./crates/data_privacy/CHANGELOG.md)
 - [`data_privacy_macros`](./crates/data_privacy_macros/CHANGELOG.md)
 - [`data_privacy_macros_impl`](./crates/data_privacy_macros_impl/CHANGELOG.md)
+- [`fetch_hyper`](./crates/fetch_hyper/CHANGELOG.md)
 - [`fundle`](./crates/fundle/CHANGELOG.md)
 - [`fundle_macros`](./crates/fundle_macros/CHANGELOG.md)
 - [`fundle_macros_impl`](./crates/fundle_macros_impl/CHANGELOG.md)