Improve tracer schema / automated logging

[svilupp]

BREAKING CHANGES

• Added new field meta to TracerMessage and TracerMessageLike to hold metadata in a simply dictionary. Change is backward-compatible.

Added

• Improved tracing by TracerSchema to automatically capture crucial metadata such as any LLM API kwargs (api_kwargs), use of prompt templates and its versions. Information is captured in meta(tracer) dictionary. See ?TracerSchema for more information.
• New tracing schema SaverSchema allows to automatically serialize all conversations. It can be composed with other tracing schemas, eg, TracerSchema to automatically capture necessary metadata and serialize. See ?SaverSchema for more information.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 92.91%. Comparing base (6ae31a5) to head (d83e966).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #151 +/- ## ========================================== + Coverage 92.84% 92.91% +0.07% ========================================== Files 42 42 Lines 3228 3262 +34 ========================================== + Hits 2997 3031 +34 Misses 231 231 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.