Add namespace support for rviz costmap cost tool (#5268)

Signed-off-by: Maurice-1235 <[email protected]>

Author: mini-1235

nav2_rviz_plugins/src/costmap_cost_tool.cpp

@@ -54,12 +54,12 @@ void CostmapCostTool::onInitialize()
   rclcpp::Node::SharedPtr node = node_ptr_->get_raw_node();
   local_cost_client_ =
     std::make_shared<nav2_util::ServiceClient<nav2_msgs::srv::GetCosts>>(
-    "/local_costmap/get_cost_local_costmap",
+    "local_costmap/get_cost_local_costmap",
     node,
     false /* Does not create and spin an internal executor*/);
   global_cost_client_ =
     std::make_shared<nav2_util::ServiceClient<nav2_msgs::srv::GetCosts>>(
-    "/global_costmap/get_cost_global_costmap",
+    "global_costmap/get_cost_global_costmap",
     node,
     false /* Does not create and spin an internal executor*/);
 }