Unity service example (#199)

* added example of implementing a UnityService

* adding tutorial for unity service

* added a couple comments to the example code

* typos and code standard fixes

* consistency: changing the service name for position_service to pos_srv

* updating the tutorial to match the corresponding script

tutorials/ros_unity_integration/README.md

 - [ROS–Unity Integration: Publisher](publisher.md) - Adding a Publisher to a Unity Scene
 - [ROS–Unity Integration: Subscriber](subscriber.md) - Adding a Subscriber to a Unity Scene
 - [ROS–Unity Integration: Service](service.md) - Adding a Service call to a Unity Scene
+- [ROS–Unity Integration: UnityService](unity_service.md) - Adding a Service that runs in a Unity Scene
 - [ROS–Unity Integration: Server Endpoint](server_endpoint.md) - How to write a Server Endpoint
 
 ## Example Unity Scripts
 - `unity_scripts/RosPublisherExample.cs`
 	- Publishes the position of a GameObject every 0.5 seconds.
 
+- `unity_scripts/RosSubscriberExample.cs`
+	- Subscribes to a topic that accepts color messages and uses them to change the color of a GameObject in the Unity scene.
+
-- `unity_scripts/RosSubscriberExample.cs`
-	- Subscribes to a topic that accepts color messages and uses them to change the color of a GameObject in the Unity scene.
+- `unity_scripts/RosUnityServiceExample.cs`
+	- Runs a service in the Unity scene that takes a GameObject's name and responds with the Pose of that object.
+

tutorials/ros_unity_integration/unity_scripts/RosUnityServiceExample.cs

         MObjectPoseServiceResponse objectPoseResponse = new MObjectPoseServiceResponse();
         // Find a game object with the requested name
         GameObject gameObject = GameObject.Find(request.object_name);
-        if (gameObject)
+        if (gameObject) 
-
+       
         return objectPoseResponse;
     }
 }

tutorials/ros_unity_integration/unity_service.md

 - Follow the [ROS–Unity Initial Setup](setup.md) guide.
 
 - Open a new terminal window, navigate to your ROS workspace, and run the following commands:
-
+  
    ```bash
     source devel/setup.bash
     rosrun robotics_demo server_endpoint.py
  ![](images/generate_messages_2.png)
 
  - The generated files will be saved in the default directory `Assets/RosMessages/RoboticsDemo/srv`.
-
+ 
 - Create a new C# script and name it `RosUnityServiceExample.cs`
 - Paste the following code into `RosUnityServiceExample.cs`
     - **Note:** This script can be found at `tutorials/ros_unity_integration/unity_scripts`.
         MObjectPoseServiceResponse objectPoseResponse = new MObjectPoseServiceResponse();
         // Find a game object with the requested name
         GameObject gameObject = GameObject.Find(request.object_name);
-        if (gameObject)
+        if (gameObject) 
-
+       
         return objectPoseResponse;
     }
 }
 - Create an empty GameObject and name it `UnityService`.
-- Attach the `RosUnityServiceExample` script to the `UnityService` GameObject.
-- Pressing play in the Editor should start running as a ROS node, waiting to accept ObjectPose requests. Once a connection to ROS has been established, a message will be printed on the ROS terminal similar to `Connection from 172.17.0.1`.
+- Attach the `RosUnityServiceExample` script to the `UnityService` GameObject. 
+- Pressing play in the Editor should start running as a ROS node, waiting to accept ObjectPose requests. Once a connection to ROS has been established, a message will be printed on the ROS terminal similar to `ROS-Unity Handshake received, will connect to 192.168.50.130:5005`.
 
 
 ## Start the Client
 
    ```bash
    Requesting pose for Cube
-   Pose for Cube:
-   position:
+   Pose for Cube: 
+   position: 
-   orientation:
+   orientation: 
      x: 0.0
      y: -0.0
      z: 0.0
    rosservice call /obj_pose_srv Cube
    ```
    ```bash
-   object_pose:
-    position:
+   object_pose: 
+    position: 
-    orientation:
+    orientation: 
       x: 0.0
       y: -0.0
       z: 0.0