Add embeddings to LLM Endpoints and use in ragas (remove reliance on .env Azure settings)

[tolgaerdonmez]

Currently, the ragas functionality relies on Azure settings provided via the .env file for embeddings. This issue proposes to:

• Add support for embeddings directly to the LLM Endpoints implementation.
• Update ragas to use the new embedding support from LLM Endpoints, removing the dependency on .env Azure settings.

This will simplify configuration, improve flexibility, and allow embedding management to be handled alongside LLM endpoints.

Acceptance Criteria:

• LLM Endpoints can provide embedding services.
• Ragas uses the embeddings from LLM Endpoints.
• The .env Azure embedding settings are no longer required for ragas.