feat: nested department sections, attaching department sections in the user editor

routers/department.py

@@ -59,6 +59,17 @@ async def delete_department(
     return await DepartmentService(session).delete_department(department_id)
 
 
+@department_router.get(
+    "/section",
+    operation_id="get_sections",
+    response_model=GetDepartmentSectionsResponse,
+)
+async def get_sections(
+        session: SessionDependency,
+):
+    return await DepartmentService(session).get_sections()
+
+
 @department_router.post(
     "/section",
     operation_id="create_section",