feat: add due date filter to KanbanFilters

- Introduced `showWithDueDate` option in `KanbanFilters` to filter tasks based on due dates.
- Added toggle button in the UI for users to easily enable/disable this filter.
- Updated `TasksContext` to handle the new filter state and applied filtering logic in task retrieval.
- Ensured user preferences are saved with the new filter option in `user-preferences.ts`.

src/lib/types.ts

@@ -71,6 +71,7 @@ export interface KanbanFilters {
   priorities?: TaskPriority[];
   showCompleted?: boolean;
   sortBy?: string;
+  showWithDueDate?: boolean;
   // Filtres spécifiques Jira
   showJiraOnly?: boolean;
   hideJiraTasks?: boolean;