Improve security of RCON

I would like to suggest making improvements to the RCON feature and/or implementing a better remote access protocol. The RCON protocol has multiple security flaws that could potentially put a server at risk, even if the RCON port is not exposed to the Internet.

The RCON password is stored in a plain text format, as it is set using the "rcon.password" value in the "server.properties" file. This means that anyone could retrieve the password by simply reading/getting a copy of the file. Storing passwords using a hash and a separate database/file would be a lot more secure.

The way RCON sends/receives data also has a huge security flaw. There is no encryption, which makes RCON vulnerable to man-in-the-middle attacks. Attacks like these can be used to gain full control of a server. The use of encryption is one of the most important defenses, as this would make it a lot more difficult for an attacker to modify the data that is being sent/received.