extraEnv values validation

[mateusoliveira43]

Fix

extraEnv values have no validation through OpenAI specification and there is no validation in Python source code for some options (like LOG_LEVEL).

Requirements

• [ ] Add OpenAI specification validation (this may require changing how it is today)
  • [ ] This can be extended for Secret and ConfigMap in env_from_configmaps and env_from_secrets options?
• [ ] https://github.com/dora-metrics/pelorus/issues/906
  • [ ] validate that even wrong options at least give user a good feedback (instead of pure Traceback)
• [ ] Check if documentation needs update

[stillalearner]

Thanks for opening an issue for this! :)