add chain id and SCW check

Sources/XMTPiOS/SigningKey.swift

@@ -19,6 +19,12 @@ import LibXMTP
 public protocol SigningKey {
 	/// A wallet address for this key
 	var address: String { get }
+
+	/// If this signing key is a smart contract wallet
+	var isSmartContractWallet: Bool { get }
+
+	/// The name of the chainId for example "eip155:1"
+	var chainId: String { get }
 
 	/// Sign the data and return a secp256k1 compact recoverable signature.
 	func sign(_ data: Data) async throws -> Signature
@@ -29,6 +35,14 @@ public protocol SigningKey {
 }
 
 extension SigningKey {
+	public var isSmartContractWallet: Bool {
+		return false
+	}
+
+	public var chainId: String {
+		return "eip155:1"
+	}
+
 	func createIdentity(_ identity: PrivateKey, preCreateIdentityCallback: PreEventCallback? = nil) async throws -> AuthorizedIdentity {
 		var slimKey = PublicKey()
 		slimKey.timestamp = UInt64(Date().millisecondsSinceEpoch)