https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt outlines the specification for the proxy protocol header, which we need to be able to parse in order to support detecting load balanced connections. In this ticket, implement a parser that supports both V1 and V2 of the proxy protocol and surfaces the original source and destination IPs parsed from the headers to a user. See SERVER-58496 for a summary of all of the work required to support load balanced connections on the server.