Add "login" parsers

[stevengreens10]

Add all parsers for the "login" state.

There are 5 packet types for clientbound packets, and 3 for serverbound packets.

Add special checks for the "Set compression" and the "Encryption request/response" parser.

Exit the program if compression or encryption is enabled as those will not be supported at first, and will prevent us from parsing the rest of the packets.

Ensure the state is being correctly handled.