Allow to change compute safekeeper list without restart.

- Add --safekeepers option to neon_local reconfigure
- Add it to python Endpoint reconfigure
- Implement config reload in walproposer by restarting the whole bgw when
  safekeeper list changes.

ref https://github.com/neondatabase/neon/issues/6341

storage_controller/src/compute_hook.rs

@@ -323,7 +323,7 @@ impl ComputeHook {
             if endpoint.tenant_id == *tenant_id && endpoint.status() == EndpointStatus::Running {
                 tracing::info!("Reconfiguring endpoint {}", endpoint_name,);
                 endpoint
-                    .reconfigure(compute_pageservers.clone(), *stripe_size)
+                    .reconfigure(compute_pageservers.clone(), *stripe_size, None)
                     .await
                     .map_err(NotifyError::NeonLocal)?;
             }