Add script to build rust-unreferenced-states tool (#1)

* Create build_unref

* Update and rename build_unref to build_unref.sh

* Update build_unref.sh

* add rust crosscompiling amd64 arm64 armhf

https://wiki.debian.org/Rust#crosscompiling

* Rework find-unref stae group script

- Factorize script
- Fix bug to make the build working
- Avoid to compress the binary as it's quite small

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Co-authored-by: Josué Tille <josue@tille.ch>

Improve the way to exclude packages

Improve the way to exclude packages

Fix small issues

Fix small issues

Fix small issues

Fix small issues

Fix small issues

Fix small issues

Fix small issues