Add changelog and fix lint issues

---

applies_to: ["server","client"]

authors: ["drganjoo"]

references: []

breaking: false

new_feature: true

bug_fix: false

---

Support for [rpcv2Cbor](https://smithy.io/2.0/additional-specs/protocols/smithy-rpc-v2.html) has been added, allowing services to serialize RPC payloads as CBOR (Concise Binary Object Representation), improving performance and efficiency in data transmission.

                // structures that might use different types for the message field.

                match decoder.str() {

                    Ok(message) => builder.message(message),

                    Err(_) => builder

                    Err(_) => builder,

                }

            }

            _ => {