feat: restructure onhost folders and naming #834

Job	Run time
codespell	12s
cargo doc	1m 38s
cargo fmt	13s
cargo clippy	2m 21s
tests as root	3m 39s
ubuntu / stable / coverage	3m 35s
Build release binaries	2m 16s
Unit test for embedded downloader	26s
K8s integration tests (part2)	10m 50s
cargo shear (unused dependencies)	12s
K8s integration tests (flux-self-update)	5m 49s
build-widows-binary	8m 32s
K8s integration tests (part1)	5m 24s
k8s-e2e-tests / K8s e2e tests infra	7m 50s
⚖️ Check third party licenses	4m 53s
Unit, docs and onhost integration tests	2m 33s
security / Rust audit scanner	2m 33s
k8s-e2e-tests / K8s e2e tests	5s
🟢 All required checks and tests pass	3s
	1h 3m 4s

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