Duplicating functions doesn't reset the GUIDs of local variables.

This is actually a bug with function duplication via UEdGraphSchema_K2::DuplicateGraph.

After a function graph is duplicated, the function entry node still retains the same GUIDs for its local variables. In this case, the user renamed one of the local variables to "MakeAMathExpressionWithMe". However, when the math expression node when to search for the local variable in the display name, it found the original variable name in the source function that the current one was duplicated from.

The fix here would be to explicitly create new GUIDs for the local variables after duplication.

1. Open any Blueprint
2. Create a new function
3. Add a new local variables named MakeAMathExpressionWithMe
4. Create a math expression node with the expression text set to "CurrentLoop_DistanceAlongSpline_Start"
5. Duplicate function
6. Open new function
7. Renamed math node to MakeAMathExpressionWithMe
8. Expected behavior: node is renamed to MakeAMathExpressionWithMe