* changed the build target of npm run build to the static folder of the spring project.
* integrated the the npm build into the maven build
* adjusted the spring config:
* removed cors configs
* added frontend config with the routes to frontend in static folder
Replaced `TemplateGenerationService` with `TemplateExportService` and introduced `ExcelMapper` classes for enhanced sheet handling. Updated the database schema to refine node predecessor handling and added new utility methods in repositories. These changes aim to improve bulk operations and data consistency.
Unused DTOs and transformation services were removed to clean up the codebase and reduce clutter. Added new utility exceptions and DTOs, including `NotFoundException`, `ReferencedException`, and `LocationDTO`, to improve error handling and code organization.
