Adds a new API call (`getAllStockPiking`) to retrieve stock picking records from the backend.
Refactors stock picking data models:
- Renames models for better clarity (e.g., `StockPickingResponse` to `StockPickingResponseModel`).
- Makes all model fields nullable to handle varying API responses gracefully.
- Introduces specific nested models (`StockPickingCompanyModel`, `StockPickingPartnerModel`, `StockPickingLocationModel`, `StockPickingTypeModel`) for related entities, enhancing type safety and data structure.
Integrates the new API call into `ReceptionPageModel` and introduces distinct loading states (`loadingUser`, `loadingReceptions`) for improved UI feedback.
Renames `AuthStruct` to `AuthModel` and `ProductStruct` to `ProductModel` to align with a consistent data model naming convention.
Updates all relevant imports, type declarations, and method signatures across the application to reflect these changes, improving codebase clarity and maintainability.
Includes minor code style improvements and refactorings in other components.
