Add Networking Support to kboot

This project introduces a network abstraction layer to libkboot, enabling boot artifacts to be fetched from remote sources without disrupting the existing loading flow. On top of this abstraction, it implements a minimal, bootloader-focused HTTP/1.1 client and HTTPS support via a TLS-backed transport. This allows kboot to support network-based boot workflows through a clean, maintainable, and extensible interface for future network features.