Add serialisation methods for Coefficients and DHPrivateKey structs, outputted when calling Participant::new(...).
Also clarify ambiguity between secret_key and private_key (private_key for private/public key pair, secret_key for symmetric encryption).
Add serialisation methods for
CoefficientsandDHPrivateKeystructs, outputted when callingParticipant::new(...). Also clarify ambiguity betweensecret_keyandprivate_key(private_keyfor private/public key pair,secret_keyfor symmetric encryption).