feat(checkout): add branch selection to reward catalog
- Add new select-branch-dropdown library with BranchDropdownComponent
and SelectedBranchDropdownComponent for branch selection
- Extend DropdownButtonComponent with filter and option subcomponents
- Integrate branch selection into reward catalog page
- Add BranchesResource for fetching available branches
- Update CheckoutMetadataService with branch selection persistence
- Add comprehensive tests for dropdown components
Related work items: #5464
feat(ui-input-controls, oms-return-process): introduce text field container, clear, and errors components
- Add `ui-text-field-container`, `ui-text-field-clear`, and `ui-text-field-errors` as standalone components for improved text field composition and error handling.
- Update SCSS to include new styles for container, clear, and errors components, ensuring visual consistency and error highlighting.
- Refactor `ReturnProcessProductQuestionComponent` to use the new containerized text field structure, improving template clarity and error display.
- Update Storybook story for `TextField` to demonstrate new composition and error handling.
- Export new components from the input-controls public API for external usage.
Ref: #4989, #5058
- Deleted validation functions for electronic devices, nonbook items, and ton/datentraeger.
- Removed associated test files for these validations.
- Updated question definitions to use new constants for item conditions and return reasons.
- Refactored return process service to utilize schema validation instead of custom validators.
- Adjusted HTML templates to reflect changes in eligibility state handling.
- ✨ **Feature**: Added customizable appearance options for CheckboxComponent
- ✨ **Feature**: Implemented ChecklistComponent for managing groups of checkboxes
- 📚 **Docs**: Added comprehensive documentation for Checkbox and Checklist components
- 🧪 **Test**: Created unit tests for ChecklistValueDirective and ChecklistComponent
