ctap2-proto: Add cosey dependency for COSE PublicKey type

Used to manage serialization and deserialization of COSE public keys
instead of coset in order to be able to derive De/Serialize for types
that include COSE public keys as fields in CBOR messages.

coset is inadequate for the purpose because it uses a distinct
AsCborSerialize trait instead of the standard serde::{Serialize,
Deserialize} traits.

crates/ctap2-proto/Cargo.toml

@@ -13,6 +13,7 @@ serde = { version = "=1.0.136", features = ["derive"], optional = true }
 typed-builder = { version = "0.14.0", default-features = false }
 # Version <= to support older serde
 serde_with = { version = "<=2.2.0", optional = true }
+cosey = "0.3.0"
 
 [dev-dependencies]
 hex = "0.4.3"