feat(core): [proxy payments] send external vault proxy metadata to UCS (#9108)

crates/hyperswitch_domain_models/src/merchant_connector_account.rs

@@ -312,6 +312,12 @@ pub struct RevenueRecoveryMetadata {
     pub mca_reference: AccountReferenceMap,
 }
 
+#[cfg(feature = "v2")]
+#[derive(Debug, Clone, serde::Deserialize)]
+pub struct ExternalVaultConnectorMetadata {
+    pub proxy_url: common_utils::types::Url,
+    pub certificate: Secret<String>,
+}
 #[cfg(feature = "v2")]
 #[derive(Debug, Clone)]
 pub struct AccountReferenceMap {