[experimental] Experiment with these crates

[radumarias]

• https://crates.io/crates/smol as a tokio replacement
• https://crates.io/crates/crossbeam for synchronization and concurrency primitives
• https://crates.io/crates/rayon it's best for parallel computing on iter. If we are to use a buffer instead of channels, we can use this to process parts of the buffer (packets) in parallel without the overhead of tokio