Local variables do not appear in the context menu inside collapsed graphs

Local variables do not appear in the context menu inside collapsed graphs. They can still be dragged into the graph.

Reproduced in 4.8 Preview 3 and Main (//depot/UE4/Promotable-CL-2560501)

1. Open any project
2. Create a new Actor Blueprint
3. Add a new function
4. Give the function a local variable
5. In the function graph, add any node (I tested with Set Actor Rotation)
6. Right click the node > Collapse Nodes
7. Double click the collapsed graph to open it
8. Right click in the collapsed graph
9. Search for the local variable

Result:
The variable will not appear in the context menu.