Restructure project layout for better CI/CD integration

- Flattened nested bootupd/bootupd/ structure to root level
- Moved all core project files to root directory
- Added proper Debian packaging structure (debian/ directory)
- Created build scripts and CI configuration
- Improved project organization for CI/CD tools
- All Rust source, tests, and configuration now at root level
- Added GitHub Actions workflow for automated testing
- Maintained all original functionality while improving structure

ci/build-test.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+set -xeuo pipefail
+test -n "${COSA_DIR:-}"
+make
+cosa build-fast
+kola run -E $(pwd) --qemu-image fastbuild-*-qemu.qcow2  --qemu-firmware uefi ext.bootupd.'*'