[open-swe] feat: Add Golang Products API microservice example

[open-swe]

Fixes #9

This PR adds a complete Golang microservice example to the repository, implementing a Products API using the Gin framework.

What's Added

• Golang Products API Service: A REST API server with full CRUD operations for product management
• Complete Project Structure: Organized with models, handlers, and proper Go module configuration
• OpenShift Deployment Script: Following the established patterns for microservice deployment
• Documentation: Updated README with deployment instructions and architecture integration details

Key Features

• REST endpoints for products (GET, POST, PUT, DELETE)
• In-memory data storage with thread-safe operations
• CORS enabled for cross-origin requests
• Health check endpoint
• Proper JSON request/response handling
• Integration with existing microservices architecture

The implementation follows the same deployment patterns as other microservices in the repository and includes proper environment variable configuration for inter-service communication.