Fix bug causing collapsed nodes to not have slots visible that should be visible

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Views/GraphEditorView.cs

                     edgeView.input = targetAnchor;
                     edgeView.input.Connect(edgeView);
                     m_GraphView.AddElement(edgeView);
+                    sourceNodeView.RefreshAnchors();
                 }
             }