Add a stub Rust crate (#12595)

.dockerignore

.github/workflows/release-artifacts.yml

.github/workflows/tests.yml

.gitignore

Cargo.toml

build_rust.py

changelog.d/12595.misc

debian/build_virtualenv

debian/changelog

debian/rules

docker/Dockerfile

docker/Dockerfile-dhvirtualenv

docs/deprecation_policy.md

docs/development/contributing_guide.md

docs/setup/installation.md

mypy.ini

poetry.lock

pyproject.toml

rust/Cargo.toml

rust/src/lib.rs