add native implementation

Author: xinsong-cui

runtime/runtime-core/native/src/aws/smithy/kotlin/runtime/hashing/EcdsaNative.kt

@@ -7,4 +7,8 @@ package aws.smithy.kotlin.runtime.hashing
 /**
  * ECDSA on the SECP256R1 curve.
  */
-public actual fun ecdsaSecp256r1(key: ByteArray, message: ByteArray): ByteArray = error("This function should not be invoked on Native, which uses the CrtAwsSigner.")
+public actual fun ecdsaSecp256r1(
+    key: ByteArray,
+    message: ByteArray,
+    signatureType: EcdsaSignatureType,
+): ByteArray = error("This function should not be invoked on Native, which uses the CrtAwsSigner.")