Add HAProxy's Proxy Protocol Support

[cube-builder]

Newer versions of PaperMC have a proxy protocol option to forward IPs from a proxy (with proxy protocol on) to the server.

It would be good to have this option in the config as I am running a VPS with DDoS Protection that has an NGINX TCP Proxy setup that goes to my backend/mc server without DDoS Protection, NGINX has an option to enable HAProxy's proxy protocol support which is what I do for my servers that I run on newer versions. It would be nice to have this for Project Poesidon so player IPs from my NGINX proxy can be forwarded to my backend/mc server.

Example with an NGINX TCP proxy:

stream {
    server {
        listen 25565;
        proxy_pass backend:25565;
        proxy_protocol on;
    }
}

[ghost]

Duplicate of #40

[RhysB]

More than happy to accept pull requests for this functionality as started in #40.

Closing this as it is a duplicate.