refactor(identity): follow naming conventions for conversion methods

This PR renames some method names that don't follow Rust naming conventions or behave differently from what the name suggests:
- Enforce "try" prefix on all methods that return `Result`.
- Enforce "encode" method name for methods that return encoded bytes.
- Enforce "to_bytes" method name for methods that return raw bytes.
- Enforce "decode" method name for methods that convert encoded key.
- Enforce "from_bytes" method name for methods that convert raw bytes.

Pull-Request: #3775.

protocols/gossipsub/src/behaviour.rs

@@ -203,7 +203,7 @@ impl From<MessageAuthenticity> for PublishConfig {
         match authenticity {
             MessageAuthenticity::Signed(keypair) => {
                 let public_key = keypair.public();
-                let key_enc = public_key.to_protobuf_encoding();
+                let key_enc = public_key.encode_protobuf();
                 let key = if key_enc.len() <= 42 {
                     // The public key can be inlined in [`rpc_proto::proto::::Message::from`], so we don't include it
                     // specifically in the [`rpc_proto::proto::Message::key`] field.