Separated LayoutDto from LayoutsController.cs into LayoutDto.cs and set its namespace to DbFirst.Application.Layouts for better code organization and maintainability.
Implemented user-customizable, persistent grid and band layouts for CatalogsGrid and MassDataGrid. Added backend API, database entity, and repository for storing layouts per user. Refactored grids to support dynamic band/column rendering, layout management UI, and per-user storage via localStorage and the new API. Registered all necessary services and updated data context. Enables flexible, user-specific grid experiences with saved layouts.
