added GameObject categorical parameter

com.unity.perception/Editor/Randomization/Uxml/CategoricalParameterTemplate.uxml

         <ListView name="options"/>
     </VisualElement>
     <VisualElement style="flex-direction: row; justify-content: flex-end;">
-        <Button name="add-option" text="Add New Option" class="add-option-button"/>
+        <Button name="add-option" text="Add Option" class="add-option-button"/>
         <Button name="clear-options" text="Clear Options" class="add-option-button"/>
     </VisualElement>
 </UXML>

com.unity.perception/Runtime/Randomization/Parameters/ParameterTypes/GameObjectParameter.cs

+using System;
+using UnityEngine.Perception.Randomization.Parameters.Attributes;
+
+namespace UnityEngine.Perception.Randomization.Parameters
+{
+    [Serializable]
+    [ParameterMetaData("GameObject")]
+    public class GameObjectParameter : CategoricalParameter<GameObject> { }
+}

com.unity.perception/Runtime/Randomization/Parameters/ParameterTypes/GameObjectParameter.cs.meta

+fileFormatVersion: 2
+guid: 434189da34ae4c34ba6e41d5d9f07a35
+timeCreated: 1597443212