[Enhancement] Client Crypto stuff/things

[phinocio]

Client really only needs to read from the .json file for itself, keeping track of its own pub/priv and peer public keys.

Flow on run of a client would be to:

• Read json config/database file
• Load its public/private keys
• Load peer(s) public key(s)
• Still need to define peer to talk to on CLI as chat is only 1:1 atm

This also requires rewriting the encrypt/decrypt functions for sending/receiving messages.