[ros_bridge][py] Add back CollisionDetector as an option.

Now that RTCs to activate is selectable from the end client (e.g. hironx.py), we need to expose all RTCs available.

hironx_ros_bridge/src/hironx_ros_bridge/hironx_client.py

@@ -316,7 +316,7 @@ class via the link above; nicely formatted api doc web page
             ['fk', "ForwardKinematics"],
             ['ic', "ImpedanceController"],
             ['el', "SoftErrorLimiter"],
-            # ['co', "CollisionDetector"],
+            ['co', "CollisionDetector"],
             ['sc', "ServoController"],
             ['log', "DataLogger"],
         ]