refactor(router): reorganize saved filters route definition

- Move the saved filters route definition outside of the nested routes list
- Simplify the builder function syntax using a fat arrow

Author: fulleni

lib/router/router.dart

@@ -775,16 +775,14 @@ GoRouter createRouter({
                           );
                         },
                       ),
-                      // Route for managing saved filters.
-                      GoRoute(
-                        path: Routes.accountSavedFilters,
-                        name: Routes.accountSavedFiltersName,
-                        builder: (context, state) {
-                          return const SavedFiltersPage();
-                        },
-                      ),
                     ],
                   ),
+                  // Route for managing saved filters.
+                  GoRoute(
+                    path: Routes.accountSavedFilters,
+                    name: Routes.accountSavedFiltersName,
+                    builder: (context, state) => const SavedFiltersPage(),
+                  ),
                 ],
               ),
             ],