Prefer NVML MIG profile names

[Shivkumar13]

Summary

• Prefer canonical NVML MIG GPU instance profile names when available.
• Fall back to the existing DCGM profile name if NVML lookup fails.
• Add coverage for the 7g.79gb to 7g.80gb correction path.

Related issue: NVIDIA/gpu-operator#687

Tests

• CGO_ENABLED=1 go test ./internal/pkg/deviceinfo ./internal/pkg/nvmlprovider
• CGO_ENABLED=1 go test ./internal/pkg/deviceinfo ./internal/pkg/nvmlprovider ./internal/pkg/transformation ./internal/pkg/watcher