Add latest Docker-DB versions

[ckunki]

Preparation

• Clone repo
• Create branch
• Read Developer Guide
• install git commit hooks

Summary

A new Docker-DB version which we need to support have been released.
https://hub.docker.com/r/exasol/docker-db/tags

function docker-db-versions () 
{ 
    local ORG=exasol;
    local REPO=docker-db;
    curl -s "https://hub.docker.com/v2/namespaces/$ORG/repositories/$REPO/tags" | jq '.results | .[] | .name'
}

Additional versions at 2024-09-17

• 7.1.27
• 7.1.28 (not available)
• 7.1.29
• 8.29.1
• 8.30.0
• 8.31.0

Compare PR #404

Task(s)

• Add config for Docker-DB X.Y.Z:
  • use symlink for 7.x versions
  • copy directory for 8.x versions
• Change default image version to X.Y.Z
• Update LATEST_DB_VERSION in test_environment_options.py
• Update currently supported version(s) in user_guide.rst, currently User Guide says --docker-db-image-version ... [default: 8.27.0]
• Update changelog