ERP/Inventory grid sample implementation

[dkamburov]

Implement an ERP/Inventory grid sample matching the design from Inventory sample in webcomponents.

Design reference:

• Showcase tracking and managing quantity, location, and details of products in stock.
• Hierarchical grid structure: supports multiple nested levels of related inventory data.
• Features: cell editing, sorting, filtering, advanced column configuration, row selection, summary, and expandable rows for details.
• Responsive layout matching the visual style of the reference sample and Material/Light theme.
• Sample Design (WebComponents)

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• Theme: Material
• Mode: Light
• See also WebComponents repo for base implementation.