Force ui update when shader might be reimported in StaticMeshOutput (#158)

Author: iTris666

com.unity.visualeffectgraph/Editor/Models/Contexts/Implementations/VFXStaticMeshOutput.cs

@@ -262,6 +262,8 @@ public override void CheckGraphBeforeImport()
             // If the graph is reimported it can be because one of its depedency such as the shadergraphs, has been changed.
             ((VFXDataMesh)GetData()).RefreshShader(); // TODO This triggers an invalidate that is theorically not needed but require to fix a bug with shader graph dependency
             ResyncSlots(true);
+
+            Invalidate(InvalidationCause.kUIChangedTransient);
         }
     }
 }