Add comprehensive Vulkan GPU support to IREE backend

[athrva98]

Features:

• Add VulkanTarget dataclass and VulkanGPUVendor enum
• Add VULKAN_TARGETS dict with 40+ GPU presets:
  • AMD: RDNA3/RDNA2 (RX 7000/6000), gfx1100/gfx1030
  • NVIDIA: Ada/Ampere/Turing (RTX 40/30/20), sm_89/sm_86/sm_75
  • Intel: Arc A-series (A770, A750)
  • ARM: Mali Valhall (G715, G710)
  • Qualcomm: Adreno
• Add IREECompileOptions dataclass with configurable:
  • opt_level (0-3), data_tiling, vulkan_target
  • opset_version for ONNX upgrade, strip_debug, const_eval
  • extra_flags for custom compiler options
• Add IREECompilationError with actionable suggestions
• Add opset_version param to emit_mlir() for ONNX compatibility

Code quality:

• Fix ruff linting (SIM102, B904, SIM115)
• Add proper exception chaining with 'from e'
• Use context manager for tempfile

Tests:

• Add TestIREECompileOptions (8 tests)
• Add TestVulkanTargets (8 tests)
• Add TestIREEErrorHandling (4 tests)
• Add TestMLIRExportWithOptions (3 tests)
• Fix test_intel_devices.py backend name assertions

Documentation:

• Update README with Vulkan GPU targets table
• Add IREE backend configuration examples
• Add troubleshooting for common IREE errors