Move to a tokio-rs style API while keeping performance the same or better

[davidtos]

https://github.com/tokio-rs/tokio-uring This project provides uring support for RUST projects. Their API looks very clean and I think it's good to move to something similar. Depending on the performance impact that it has.

use tokio_uring::fs::File;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    tokio_uring::start(async {
        // Open a file
        let file = File::open("hello.txt").await?;

        let buf = vec![0; 4096];
        // Read some data, the buffer is passed by ownership and
        // submitted to the kernel. When the operation completes,
        // we get the buffer back.
        let (res, buf) = file.read_at(buf, 0).await;
        let n = res?;

        // Display the contents
        println!("{:?}", &buf[..n]);

        Ok(())
    })
}