Implement OpenGauss vector database integration for Llama Stack with the following features:
- Add OpenGaussVectorIOAdapter for vector storage and retrieval
- Support native vector similarity search operations
- Implement connection and query management with psycopg2
- Provide configuration template for easy setup
- Add comprehensive unit tests
The implementation allows Llama Stack users to leverage OpenGauss as an
enterprise-grade vector database for RAG applications. Users can configure
their environment through a simple YAML configuration and environment variables.
