Defines types that give a cryptographic identity to every Participant. This chiefly includes secret keys, public keys, and signatures.
Defines types and encodings that are used in messages exchanged between Participants. The wire-encodings of these types are an
integral part of the protocol, and all Participant implementations that wish to communicate with the implementation in this crate
needs to encode these types in the exact same way.
Defines additional types that the Block Tree’s storage implementation needs to store to support its functionality, but which are
not sent over the wire and therefore are not part of the protocol. An example functionality of the Block Tree that requires these
additional types is getting the child of a Block, since a msg_types::Block only stores a pointer to its parent in the form of
justify.block_hash.