Migrate staging's elasticsearch inside k8s using the ECK operator

It's a POC to evaluate the capacity of the eck-operator to manage elasticsearch instances. The POC can be done without unplugging esnode0 until the deployment is fully validated and stressed.

• Deployed an elasticsearch cluster with 3 nodes
• Trigger a search journal client to reindex the data
• Monitor the elasticsearch cluster [1]
• Chaos monkey tests
  • Increase replica to 3 (from 1) ~> operator deals with the replicas and sharding
  • Upgrade operator (current version 2.13, latest 2.15)
  • Restart deployment (rollout)
  • Kill a pod (out of a cluster with 3 replicas)
  • Kill 2 pods (out of a cluster with 3 replicas)
  • ...
• swh/infra/ci-cd/swh-charts!530 (merged): Migrate the staging search instance using the new elasticsearch instance running in kube

Note: It's the ELK stack but the official operator is named eck-operator

[1] https://grafana.softwareheritage.org/goto/Yvb3a2VHz?orgId=1