feat(connector): [Airwallex] add multiple redirect support for 3DS (#811)

Co-authored-by: Narayan Bhat <narayan.bhat@juspay.in>
Co-authored-by: Jagan Elavarasan <jaganelavarasan@gmail.com>

crates/api_models/src/payments.rs

@@ -1222,6 +1222,8 @@ pub struct Metadata {
     #[schema(value_type = Object, example = r#"{ "city": "NY", "unit": "245" }"#)]
     #[serde(flatten)]
     pub data: pii::SecretSerdeValue,
+    /// Payload coming in request as a metadata field
+    pub payload: Option<pii::SecretSerdeValue>,
 }
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone, ToSchema)]