[OPIK-444] [SDK] Update OpenAI integration to support logging model and provider in a new format

[japdubengsub]

Details

Added model and provider handling for OpenAI integration. If OpenAI client was initialized with specific base URL - it will be put in provider span attribute instead of openapi.

Issues

Resolves #

Testing

e2e test updated

Documentation

[alexkuzmik]

Lets not merge until Monday discussion.