Executable mods

[est31]

Expansion of #5. Have executable components of mods serverside as well as clientside.

• Server sends executable components to client
• Runtime: wasm/wasm-wasi based. Wasm supports wide array of languages. TODO Ctrl+f this document for all the Rust based wasm runtimes, perform comparison based on benchmarks, time to build, feature set, etc. At the start I guess a simpler implementation would be enough though.
• Languages for natively shipped mods: Either Rust or tinygo, not 100% sure yet