Define test automation scenario for Redis cache.
Requirements:

• Automated setup of Redis in a RHDH namespace is implemented and functional
• Automated connection of RHDH to an external cache is implemented and verified
• Automated validation of cache usage with RBAC plugin is implemented, including:
  • Scaling out deployment to 2 pods
  • Checking specific keys in Redis
• Developer setup for testing local Redis setups with containers is provided
• Cache functionality in horizontally scaled RHDH deployments is validated

See alos https://issues.redhat.com/browse/RHIDP-1994 for the RBAC usage of cache.