Evaluate potential Gatling successors

[kami619]

Evaluate the tool based on the below heuristics,

• Supported Language - Preferably Java support
• Support for concurrent execution of scenarios
• Support for dynamic data injection and ability to control the run based on target objectives
• Able to generate detailed reports with long tail percentiles for latency, throughput rate, error distribution, latency distribution and time-series graphs with the ability to plot both client-side and server-side errors
  • Bonus points for having native support for Prometheus and/or Grafana visualization.
• Ability to monitor the performance test run when the load test run is happening.
• Using a license approved by the CNCF, or a open source friendly license with an exception granted by the CNCF
• Should be able to integrate with the existing dataset module
• Should have very close features that can support the existing kcb.sh feature flags
  https://github.com/keycloak/keycloak-benchmark/blob/main/benchmark/src/main/content/bin/kcb.sh#L62-L77
  https://github.com/keycloak/keycloak-benchmark/blob/main/benchmark/src/main/java/org/keycloak/benchmark/Config.java
• Should supported the SLO/SLI metrics based load tests, this could bring us closer to our long term vision (this goal needs to be discussed with the team in detail)