feat: add country fetching API endpoint and implement dashboard contributions management

- Implemented a new API endpoint for fetching countries with pagination support.
- Added a new Svelte component for managing contributions in the dashboard, including CRUD operations for contributions and general contributions.
- Introduced dynamic tab navigation for different contribution types (DTA, PREV, ECI, MULT, REC).
- Enhanced user interface with dialogs for adding and editing contributions and general contributions.

backend/api/v1/modules/public/reference_data/countries/routes.py

@@ -16,8 +16,8 @@ async def list_countries(
     page: int = Query(1, ge=1, description="Número de página"),
     page_size: int = Query(50, ge=1, le=100, description="Tamaño de página"),
     db: Session = Depends(get_core_db),
-    current_user: dict = Depends(get_current_user),
 ):
+    """Endpoint público para obtener lista de países - no requiere autenticación"""
     skip = (page - 1) * page_size
     query = db.query(Country)
     items = query.offset(skip).limit(page_size).all()