Refined `ModificationScope` with `.Topological`

`Topological` represents something that changes the topology of the
graph, i.e. something that causes e.g. edge removal.

MaterialGraphProject/Assets/GraphFramework/SerializableGraph/Editor/Drawing/AbstractGraphDataSource.cs

                     drawableNodeData.OnModified(scope);
             }
 
+            if (scope == ModificationScope.Topological)
+                UpdateData();
+
             EditorUtility.SetDirty(graphAsset.GetScriptableObject());
         }
 

MaterialGraphProject/Assets/GraphFramework/SerializableGraph/Runtime/Interfaces/INode.cs

 {
     public enum ModificationScope
     {
-        Nothing,
-        Node,
-        Graph
+        Nothing = 0,
+        Node = 1,
+        Graph = 2,
+        Topological = 3
     }
 
     public delegate void OnNodeModified(INode node, ModificationScope scope);

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/DrawData/NodePreviewDrawData.cs

             set
             {
                 // External changes can only set the modification scope higher, to prevent missing out on a previously set shader regeneration.
-                if (m_modificationScope == ModificationScope.Graph || (m_modificationScope == ModificationScope.Node && value == ModificationScope.Nothing))
+                if (m_modificationScope >= value)
                     return;
                 m_modificationScope = value;
             }
             if (m_modificationScope != ModificationScope.Nothing)
             {
                 bool status = false;
-                if (m_modificationScope == ModificationScope.Graph)
+                if (m_modificationScope >= ModificationScope.Graph)
                 {
                     previewGenerator.Reset();
 

MaterialGraphProject/Assets/UnityShaderEditor/Runtime/Remapper/MasterRemapInputNode.cs

 
             if (onModified != null)
             {
-                onModified(this, ModificationScope.Graph);
+                onModified(this, ModificationScope.Topological);
             }
 
             return -nextSlotId;
 
             if (onModified != null)
             {
-                onModified(this, ModificationScope.Graph);
+                onModified(this, ModificationScope.Topological);
             }
         }
 

MaterialGraphProject/Assets/UnityShaderEditor/Runtime/Remapper/RemapMasterNode.cs

                 OnEnable();
 
                 if (onModified != null)
-                    onModified(this, ModificationScope.Graph);
+                    onModified(this, ModificationScope.Topological);
             }
         }
 #else

MaterialGraphProject/Assets/UnityShaderEditor/Runtime/SubGraph/SubGraphNode.cs

                 OnEnable();
 
                 if (onModified != null)
-                    onModified(this, ModificationScope.Graph);
+                    onModified(this, ModificationScope.Topological);
             }
         }