WIP: Boilerplatey stuff

[tcmal]

• Add tracing and some other related crates for logging and profiling.
• Add config for loading config from environment and file (mostly convenience)
• Add docker-compose.dev.yml file and nix configuration, incl building docker image using nix
• Switch to async redis/deadpool_redis and sqlx instead of sync
• Add opentelemetry exporter so trace information can be viewed in grafana
• Add a RequestError type that can be used to represent internal/external errors instead of panicking.
• Add instructions on how to set up proxy for development
• Fix some clippy lints

The resulting telemetry (in debug mode) looks like this in grafana:

[mayacopeland]

Everything looks fine, there'll be some changes I'll need to make afterwards with redis anyway, atleast for player buffers in order to not lose packets because someone wrote something to the buffer as we're flushing it.