Test a non-k8s HA Clickhouse install on EC2 and document instructions

[abhinavg6]

For self-managed Weave for some customers, we may need to provide support to self-manage an open-source Clickhouse install without Kubernetes. This ask is to test / PoC such an install on AWS EC2 using Clickhouse stable docker image and document it such that it could be shared with customers. Also, see if it's possible to use S3 as the backend storage, though EBS volumes may be needed for some part.

Some references:

• https://clickhouse.com/docs/en/install#available-installation-options
• https://hub.docker.com/r/clickhouse/clickhouse-server/
• https://clickhouse.com/docs/en/architecture/cluster-deployment
• https://www.propeldata.com/blog/clickhouse-docker
• https://github.com/n0vad3v/simple-multinode-clickhouse-cluster

[abhinavg6]

cc @raubitsj