Right-click menu for JKI SM gives inconsistent state if using a utility node alone

[francois-normandin]

If using any of the utility nodes without the whole JKI SM loop, right-click menu on an empty string constant gives an inconsistent menu item at the top of the menu. Selecting "String Palette" simply does nothing, so this is not a showstopper but might need to be filtered out when not state machine exists.