`RadioPayloadMessage` should be a trait, not a struct This trait need to require: 1. Everything on `GraphcastMessage` currently 2. Set of required functions - `decode` - `validity_check` - `build` 3. Set of required fields - `graph_account` - `nonce`
RadioPayloadMessageshould be a trait, not a structThis trait need to require:
GraphcastMessagecurrentlydecodevalidity_checkbuildgraph_accountnonce