Fixes for subgraph, preview and property nodes

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Data/Nodes/Input/Basic/PropertyNode.cs

 
 namespace UnityEditor.ShaderGraph
 {
-    [Title("Property Node")]
+    [Title("Input", "Property")]
     public class PropertyNode : AbstractMaterialNode, IGeneratesBodyCode, IOnAssetEnabled
     {
         private Guid m_PropertyGuid;

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Data/Nodes/Utility/PreviewNode.cs

 
 namespace UnityEditor.ShaderGraph
 {
-    [Title("Preview Node")]
+    [Title("Utility", "Preview")]
     public class PreviewNode : CodeFunctionNode
     {
         public override bool hasPreview { get { return true; } }
         }
 
         static string Unity_Preview(
-            [Slot(0, Binding.None)] DynamicDimensionVector input,
-            [Slot(1, Binding.None)] out DynamicDimensionVector output)
+            [Slot(0, Binding.None)] DynamicDimensionVector In,
+            [Slot(1, Binding.None)] out DynamicDimensionVector Out)
-    output = input;
+    Out = In;
 }
 ";
         }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Data/Nodes/Utility/SubGraphNode.cs

 
 namespace UnityEditor.ShaderGraph
 {
-    [Title("Sub-graph", "Sub-graph Node")]
+    [Title("Utility", "Sub-graph")]
     public class SubGraphNode : AbstractSubGraphNode
         , IGeneratesBodyCode
         , IOnAssetEnabled
 
         public SubGraphNode()
         {
-            name = "SubGraph";
+            name = "Sub-graph";
         }
 
         public void GenerateNodeCode(ShaderGenerator shaderBodyVisitor, GenerationMode generationMode)