Integrated Micrometer's Observation into the OpenAiChatModel#stream reactive chain.

Included changes:

  • Added ability to aggregate streaming responses for use in Observation metadata.
  • Improved error handling and logging for chat response processing.
  • Updated unit tests to include new observation logic and subscribe to Flux responses.
  • Refined validation of observations in both normal and streaming chat operations.
  • Disabled retry for streaming which used RetryTemplate - should use .retryWhen operator as the next step.
  • Added an integration test.

This PR is a joint effort with @tzolov.

Resolves #1190

Comment From: tzolov

Thanks you @chemicL Rebased, squashed and merged at 478f180297d57f522d63d83f1cf71b7a2510aee5