#73 Add GreenCopper JS Runtime

[joepio]

WIP plugin system for Atomic Server powered by the GreenCopperRuntime, a very promising Rust crate that enables running JS code from Rust.

so much thanks to @HiRoFa for helping me out!

PR Checklist:

• [x] Link to related issue #73
• [ ] Add changelog entry linking to issue
• [ ] Added tests (if needed)
• [ ] (If new feature) added in description / readme