feat: Normalize the output format of 'balance_operation_count'

Author: acelyc111

src/meta/greedy_load_balancer.cpp

@@ -104,7 +104,7 @@ std::string greedy_load_balancer::get_balance_operation_count(const std::vector<
     } else {
         info["error"] = fmt::format("invalid arguments");
     }
-    return info.dump(2);
+    return info.dump();
 }
 
 void greedy_load_balancer::score(meta_view view, double &primary_stddev, double &total_stddev)

src/meta/meta_service.cpp

@@ -736,7 +736,7 @@ void meta_service::on_query_cluster_info(configuration_cluster_info_rpc rpc)
         _meta_function_level_VALUES_TO_NAMES.find(get_function_level())->second + 3);
     response.keys.push_back("balance_operation_count");
     std::vector<std::string> balance_operation_type;
-    balance_operation_type.emplace_back(std::string("detail"));
+    balance_operation_type.emplace_back("detail");
     response.values.push_back(_balancer->get_balance_operation_count(balance_operation_type));
     double primary_stddev, total_stddev;
     _state->get_cluster_balance_score(primary_stddev, total_stddev);