heal legacy objects when versioning is enabled after upgrade (#13671)
```

- A security fix must be backported if a customer is affected by it, we have a mechanism in SUBNET to send out notifications to affected customers in such situations, this is a mandatory requirement.

```
commit 99bf4d0c429f04dbd013ba98840d07b759ae1702 (tag: RELEASE.2019-06-15T23-07-18Z)
Author: Harshavardhana <******@****.***>

notify_webhook        publish bucket notifications to webhook endpoints
notify_amqp           publish bucket notifications to AMQP endpoints
notify_kafka          publish bucket notifications to Kafka endpoints
notify_mqtt           publish bucket notifications to MQTT endpoints
notify_nats           publish bucket notifications to NATS endpoints
notify_nsq            publish bucket notifications to NSQ endpoints

- BucketWebsite (Use [`caddy`](https://github.com/caddyserver/caddy) or [`nginx`](https://www.nginx.com/resources/wiki/))
- BucketAnalytics, BucketMetrics, BucketLogging (Use [bucket notification](https://min.io/docs/minio/linux/administration/monitoring/bucket-notifications.html) APIs)

### List of Amazon S3 Object API's not supported on MinIO

> NOTE: Bucket versioning is automatically enabled for all new and existing buckets on all replicated sites.

The following Bucket features will **not be replicated**, is designed to differ between sites:

- Bucket notification configuration
- Bucket lifecycle (ILM) configuration

## Pre-requisites

| `minio_cluster_notification_current_send_in_progress` | `counter` | Number of concurrent async Send calls active to all targets                              |        |
| `minio_cluster_notification_events_errors_total`      | `counter` | Events that were failed to be sent to the targets                                        |        |

| `minio_inter_node_traffic_received_bytes` | Total number of bytes received from other peer nodes.   |
| `minio_inter_node_traffic_sent_bytes`     | Total number of bytes sent to the other peer nodes.     |

## Bucket Notification Metrics

| Name                                           | Description                                                                                                                                 |

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