Add node pop-up appears in top-left of graph window when pressing space

Steps to reproduce:

1. Create and open an empty project and install com.unity.behavior

1. Add new Behavior Graph in the Assets folder (Create → Behavior → Behavior Graph)

1. Open the created Behavior Graph

1. Press the Space key on the keyboard

Actual results: The add menu appears in the top-left corner of the window

Expected results: The add menu appears right below the cursor

Reproducible with versions: 
1.0.8
1.0.7

Not reproducible with versions: 
1.0.6

Tested on (OS): MacOS

Note

• Not reproducible on Windows