ContextMenu: If there's no MenuBar, F9 should open/close the context menu

[tig]

Totally a minor issue, but it would be a nice enhancement to make things more consistent.

But consider this: If there IS a MenuBar, and a Context Menu is open, what should F9 do?

[BDisp]

But consider this: If there IS a MenuBar, and a Context Menu is open, what should F9 do?

Would open the MenuBar. ContextMenu has his own key binding.

[tig]

But consider this: If there IS a MenuBar, and a Context Menu is open, what should F9 do?

Would open the MenuBar. ContextMenu has his own key binding.

And the Context Menu would close?

[BDisp]

And the Context Menu would close?

Yes, it should. Otherwise have to be fixed.

[BDisp]

Related to #2121. @tig can this be closed?