INFRA - GitHub Actions CI

[davidbeechey]

Add basic "Cargo Build & Test" and "Linter" workflows.

Linter:

• Runs clippy
• Checks for TODOs
• Enforces LF

(Currently fails because we have no Rust to build...)

To Do:

• Spell check

[kshxtij]

LGTM, some other random rust CI tools i've run into which you could consider are:

1. https://crates.io/crates/typos
2. https://crates.io/crates/cargo-audit
3. https://rust-lang.github.io/rustfmt/ to enforce code style (the rust lsp respects a root rustfmt.toml as well and this can enforce line endings)

There's also yamlfmt if we forsee ourself using lots of yaml configs but otherwise it's probably not needed.

[TomLonergan03]

lgtm