feat: refactor icon system to nested product hierarchy

- Restructure product layer above base/user layers with nested structure
- Move src/assets/Icons/animal/* to src/assets/Icons/product/animal/base/
- Update src/components/Icon/iconRegistry.ts with new nested path resolution logic
- Add backward compatibility for old flat product structure
- Update src/components/Icon/index.tsx to support new layer types
- Add src/components/Icon/test-product-layer.tsx for testing new hierarchy
- Add src/components/Icon/README.md with comprehensive documentation
- New priority: custom > product-custom > product-base > base
- Support both new nested and legacy flat product structures

src/assets/Icons/product/animal/base/module-common/icon-info.json

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+{}

src/assets/Icons/product/animal/base/module-configuration/icon-info.json

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+{}

src/assets/Icons/product/animal/base/module-device/icon-info.json

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+{}

src/assets/Icons/product/animal/base/module-exam/icon-info.json

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+{}

src/assets/Icons/product/animal/base/module-output/icon-info.json

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+{}

src/assets/Icons/product/animal/base/module-patient/icon-info.json

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+{}

src/assets/Icons/product/animal/base/module-process/icon-info.json

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+{}