Add change notifications for shader properties

MaterialGraphProject/Assets/GraphFramework/SerializableGraph/Runtime/Implementation/SerializableGraph.cs

 
         public OnGraphChange onChange { get; set; }
 
-        void NotifyChange(GraphChange change)
+        protected void NotifyChange(GraphChange change)
         {
             if (onChange != null)
                 onChange(change);

MaterialGraphProject/Assets/UnityShaderEditor/Runtime/Graphs/AbstractMaterialGraph.cs

                 return;
 
             m_Properties.Add(property);
+            NotifyChange(new ShaderPropertyAdded(property));
-            m_Properties.RemoveAll(x => x.guid == guid);
+            if (m_Properties.RemoveAll(x => x.guid == guid) > 0)
+                NotifyChange(new ShaderPropertyRemoved(guid));
         }
 
         public override Dictionary<SerializationHelper.TypeSerializationInfo, SerializationHelper.TypeSerializationInfo> GetLegacyTypeRemapping()

MaterialGraphProject/Assets/UnityShaderEditor/Runtime/Interfaces/MaterialGraphChange.cs

+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using UnityEngine.Graphing;
+
+namespace UnityEngine.MaterialGraph
+{
+    public class ShaderPropertyAdded : GraphChange
+    {
+        public ShaderPropertyAdded(IShaderProperty shaderProperty)
+        {
+            this.shaderProperty = shaderProperty;
+        }
+
+        public IShaderProperty shaderProperty { get; private set; }
+    }
+
+    public class ShaderPropertyRemoved : GraphChange
+    {
+        public ShaderPropertyRemoved(Guid guid)
+        {
+            this.guid = this.guid;
+        }
+
+        public Guid guid { get; private set; }
+    }
+}

MaterialGraphProject/Assets/UnityShaderEditor/Runtime/Interfaces/MaterialGraphChange.cs.meta

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