feat(refunds): add connector field in refund response (#1059)

Co-authored-by: Sarthak Soni <76486416+Sarthak1799@users.noreply.github.com>

crates/router/src/core/refunds.rs

@@ -669,6 +669,7 @@ impl ForeignFrom<storage::Refund> for api::RefundResponse {
             error_code: refund.refund_error_code,
             created_at: Some(refund.created_at),
             updated_at: Some(refund.updated_at),
+            connector: refund.connector,
         }
     }
 }