feat(core): Add ability to verify connector credentials before integrating the connector (#2986)

Co-authored-by: hyperswitch-bot[bot] <148525504+hyperswitch-bot[bot]@users.noreply.github.com>

crates/router/src/core.rs

@@ -28,4 +28,6 @@ pub mod user;
 pub mod utils;
 #[cfg(all(feature = "olap", feature = "kms"))]
 pub mod verification;
+#[cfg(feature = "olap")]
+pub mod verify_connector;
 pub mod webhooks;