Add Rust CI workflow to run quickstart example

[thunderbiscuit]

This PR brings in a CI workflow that builds and runs the quickstart Rust example.

We can expand on this as time goes and add more examples; this is an MVP of the workflow. You can see that it succeeds on master here.

[riverKanies]

looks sweet!
the full wallet example will include transaction broadcasting so that's something we may not be able to include in CI... not sure if you have thoughts on that. One possible direction would be to break the code down into functions to test individually... but that would clutter up the example code in a way

[thunderbiscuit]

Yeah I'd rather keep the examples clean for sure.