Add unwrap tests for normal and stone errors

Introduce tests to validate the behavior of the Unwrap function for both standard errors and StoneError instances. Ensure correct handling of wrapped errors and verify type identification with IsStoneError checks.

error_test.go

@@ -33,6 +33,32 @@ func Test_StoneWrap(t *testing.T) {
 	t.Log(stoneError)
 }
 
+func Test_NormalUnwrap(t *testing.T) {
+	normalError := errors.New("test")
+	stoneError := Wrap(normalError, 1, "test")
+
+	unwrap := stoneError.Unwrap()
+
+	if IsStoneError(unwrap) {
+		t.Fail()
+	} else {
+		t.Log(stoneError)
+	}
+}
+
+func Test_StoneUnwrap(t *testing.T) {
+	normalError := New(1, "test")
+	stoneError := Wrap(normalError, 1, "test")
+
+	unwrap := stoneError.Unwrap()
+
+	if !IsStoneError(unwrap) {
+		t.Fail()
+	} else {
+		t.Log(stoneError)
+	}
+}
+
 func Test_ToJSON(t *testing.T) {
 	stoneError := New(1, "test").
 		WithMetadata("key", "value").