Use AddComponentMenu for MonoBehaviours (#3231)

* Set AddComponentMenu for MonoBehaviours

* don't add Monitor

* pass componentOrder instead of nesting

UnitySDK/Assets/ML-Agents/Scripts/DemonstrationRecorder.cs

     /// Demonstration Recorder Component.
     /// </summary>
     [RequireComponent(typeof(Agent))]
+    [AddComponentMenu("ML Agents/Demonstration Recorder", (int) MenuGroup.Default)]
     public class DemonstrationRecorder : MonoBehaviour
     {
         public bool record;

UnitySDK/Assets/ML-Agents/Scripts/Policy/BehaviorParameters.cs

     /// <summary>
     /// The Factory to generate policies.
     /// </summary>
+    ///
+    [AddComponentMenu("ML Agents/Behavior Parameters", (int) MenuGroup.Default)]
     public class BehaviorParameters : MonoBehaviour
     {
 

UnitySDK/Assets/ML-Agents/Scripts/Sensor/CameraSensorComponent.cs

 
 namespace MLAgents.Sensor
 {
+    [AddComponentMenu("ML Agents/Camera Sensor", (int) MenuGroup.Sensors)]
     public class CameraSensorComponent : SensorComponent
     {
         public new Camera camera;

UnitySDK/Assets/ML-Agents/Scripts/Sensor/ISensor.cs

             return count;
         }
     }
-
 }

UnitySDK/Assets/ML-Agents/Scripts/Sensor/RayPerceptionSensorComponent2D.cs

+using UnityEngine;
+
+    [AddComponentMenu("ML Agents/Ray Perception Sensor 2D", (int) MenuGroup.Sensors)]
     public class RayPerceptionSensorComponent2D : RayPerceptionSensorComponentBase
     {
         public override RayPerceptionSensor.CastType GetCastType()

UnitySDK/Assets/ML-Agents/Scripts/Sensor/RayPerceptionSensorComponent3D.cs

 
 namespace MLAgents.Sensor
 {
+    [AddComponentMenu("ML Agents/Ray Perception Sensor 3D", (int) MenuGroup.Sensors)]
     public class RayPerceptionSensorComponent3D : RayPerceptionSensorComponentBase
     {
         [Header("3D Properties", order = 100)]

UnitySDK/Assets/ML-Agents/Scripts/Sensor/RenderTextureSensorComponent.cs

 
 namespace MLAgents.Sensor
 {
+    [AddComponentMenu("ML Agents/Render Texture Sensor", (int) MenuGroup.Sensors)]
     public class RenderTextureSensorComponent : SensorComponent
     {
         public RenderTexture renderTexture;

UnitySDK/Assets/ML-Agents/Scripts/Constants.cs

+namespace MLAgents
+{
+    /// <summary>
+    /// Grouping for use in AddComponentMenu (instead of nesting the menus).
+    /// </summary>
+    public enum MenuGroup
+    {
+        Default=0,
+        Sensors=50
+    }
+}

UnitySDK/Assets/ML-Agents/Scripts/Constants.cs.meta

+fileFormatVersion: 2
+guid: 0622d88401ec464d9d2cf2fb03ce17b5
+timeCreated: 1579215785