Add Intel Arc Battlemage (BMG) GPU XPU support and Code Translation enhancements

[tintisimone]

…nhancements

Add Intel Arc Battlemage (BMG) GPU support with XPU backend:

• Add Intel GPU Plugin for Kubernetes deployment
• Support XPU device type alongside CPU and HPU (Gaudi)
• Add vLLM XPU backend configuration with intel/vllm:0.14.0-xpu image
• Add BMG-specific Helm values and deployment templates
• Add 6 BMG-optimized models (Llama, Mistral, DeepSeek, Qwen, Falcon3)
• Default to Qwen/Qwen2.5-Coder-3B-Instruct for testing
• Add gpu.intel.com/xe resource management for Ubuntu 25.10
• Add comprehensive BMG deployment documentation
• Add single-node XPU configuration examples

Code Translation improvements:

• Update API client for XPU deployment compatibility
• Update docker-compose configuration

Refactoring:

• Replace cpu_or_gpu parameter with device (cpu/hpu/xpu)
• Update all deployment scripts and configuration files
• Add XPU-specific environment variables for vLLM
• Improve model selection logic for multi-device support