Consul assess breaking changes in chart upgrade

We use a deprecated Helm chart: https://github.com/hashicorp/consul-helm

Investigate how we can upgrade to using the new chart https://github.com/hashicorp/consul-k8s and if any breaking changes were introduced.

Deployment: https://gitlab.com/gitlab-com/gl-infra/k8s-workloads/gitlab-helmfiles/-/tree/master/releases/consul

• How can we migrate between charts
• Can we upgrade the clients before the servers
• Does it require any downtime/manual intervention