Log all messages sent

[atoulme]

Add the ability to log all messages to stdout. The log line should be timestamped. The contents of the message should be shown, though the portion of the message containing random bytes should be ignored.

[adam-hanna]

May need to modify gossip sub source code, not 100% certain though. The protocol automatically handles all message sending I don't know of any hooks I can use to log on message send.