Add Support for Configuring CCR Setup

[jherns]

• Add docker compose profile for setting up a leader and follower ES clusters
• Add script to apply non-prod license to both clusters and setup remote connection

Next steps will be adding API support for ccr and testing it with this setup

[Copilot]

PR Overview

This pull request adds support for an ES 8 cross cluster replication (CCR) setup, introducing a new follower cluster service that can be run alongside the existing Elasticsearch services. Notable updates include additions to the Docker Compose file for the follower cluster and new configuration files to enable remote cluster connections.

• Added a new "ccr" profile in docker/compose.yaml for cross cluster replication.
• Added a new Elasticsearch follower service in docker/compose.yaml along with a corresponding elasticsearch-follow.yml file.
• Updated elasticsearch8plus.yml to define a remote_cluster.port.
• Updated README.md with instructions for running ES 8 in CCR mode.

Changes

File	Description
docker/compose.yaml	Added CCR profile and new follower service configuration for Elasticsearch
docker/elasticsearch8plus.yml	Added remote cluster port configuration
docker/elasticsearch-follow.yml	New configuration file for the Elasticsearch follower cluster
README.md	Added instructions for running cross cluster replication mode in ES 8

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

docker/compose.yaml:57

• [nitpick] Consider using a distinct environment variable for the follower service’s port to avoid potential confusion and ensure clear separation of port configurations.

-      - 127.0.0.1:${ES_8_PORT:-9209}:9201

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[dtaivpp]

Can we upgrade this to 1G for XMX & XMS? I've seen flakyness before with this little memory assigned to the JVM.