tests: add end-to-end testing

[beeb]

Potentially using https://hub.docker.com/r/adobe/s3mock/

let shared_config = aws_config::from_env()
        .region(params.aws_region.region().await)
        .endpoint_url(endpoint_url) // use the local URL if testing
        .load()
        .await;

More reading material:

https://docs.rs/dockertest/latest/dockertest/

https://docs.rs/testcontainers/latest/testcontainers/