feat: stabilize wait and read index and lsn API

Closes #274 (closed) Closes #175 (closed)

src/governor/mod.rs

@@ -209,7 +209,7 @@ impl Loop {
                         "instance_id" => %instance_id
                     ]
                     async {
-                        let rpc::sync::Response { applied } = pool
+                        let rpc::sync::WaitResponse { applied } = pool
                             .call(instance_id, &rpc)?
                             .timeout(Loop::SYNC_TIMEOUT)
                             .await?;