Draft: Implement human grouping

Closes #34

source/armarx/navigation/components/navigator/Component.cpp

@@ -251,7 +251,10 @@ namespace armarx::navigation::components::navigator
             fac::NavigationStackFactory::create(stackConfig, sceneProvider->scene());
 
         // set visualization of LocalPlanner
-        stack.localPlanner->setVisualization(getArvizClient());
+        if (stack.localPlanner)
+        {
+            stack.localPlanner->setVisualization(getArvizClient());
+        }
 
         memoryIntrospectors.emplace_back(
             std::make_unique<server::MemoryIntrospector>(resultsWriterPlugin->get(), callerId));