Fixes scheduler-side KV connector stats collection so that:
1. update_connector_output() runs before scheduler-side stats are collected.
2. worker-side and scheduler-side KV connector stats are aggregated when both are present.
3. scheduler-only KV connector stats are still emitted when no worker-side stats exist.
Signed-off-by: srinivas_oo7 <sklinkedin0120@gmail.com>
Co-authored-by: srinivas_oo7 <sklinkedin0120@gmail.com>