(fix) make plugins optional and fix tsdf occupancy parameter

Author: nathanhhughes

hydra_ros/config/sinks/active_window_sinks.yaml

@@ -8,5 +8,4 @@ sinks:
       type: UniformMeshColoring
       color: [255, 0, 0]
   - type: TsdfOccupancyPublisher
-    extraction:
-      min_distance: 0.25
+    min_distance: 0.25

hydra_visualizer/include/hydra_visualizer/visualizer_node.h

@@ -53,7 +53,7 @@ class DsgVisualizer {
     SceneGraphRenderer::Config renderer;
     config::VirtualConfig<GraphWrapper> graph;
     // Specify additional plugins that should be loaded <name, config>
-    std::map<std::string, config::VirtualConfig<VisualizerPlugin>> plugins;
+    std::map<std::string, config::VirtualConfig<VisualizerPlugin, true>> plugins;
   } const config;
 
   //! Construct the visualizer from a config