Add Proxy Protocol

[ggrandes]

Reference: https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt

[ggrandes]

References:

• https://github.com/apache/mina-sshd/tree/90872df67562818d0a23be61b3ec82f67cbc62b6/sshd-contrib/src/main/java/org/apache/sshd/contrib/server/session/proxyprotocol
• https://github.com/apache/mina-sshd/tree/90872df67562818d0a23be61b3ec82f67cbc62b6/sshd-contrib/src/main/java/org/apache/sshd/contrib/server/session/proxyprotocolv2