Dynamic Provider: Support multiple providers #240

Is your feature request related to a problem?
The current dynamic provider only supports OpenAI configurations, which limits its functionality. As Google batch evaluation integration is required, the system needs to accommodate various providers to ensure usability in staging and production.

Describe the solution you'd like
Make the dynamic provider agnostic by:

• Supporting multiple providers in the configuration
• Dynamically listing configurations based on the selected provider and model
• Showing only the completion types supported by the respective provider