Include LLM analytics in the evaluation mode experiments results

[FelixTJDietrich]

Is your feature request related to a problem?

Currently the LLM analytics data is missing when exporting the experiment results after conducting an evaluation using the playground.

Describe the solution you'd like

The Athena Playground should be able to request the analytics data from Athena during export. This can be a global endpoint that uses the already included header information to request the right traces from LangSmith or LangFuse in the future.

Describe the alternatives you've considered

Exporting it manually using a separate script that is not integrated. Not good if an instructor wants to conduct an experiment.

Additional context

No response