MenuBar does not disappear if mouse leaves when poe is not open

[Tartarus762]

Describe the bug
When poe is not open, mousing over the location of the MenuBar dialog causes it to become visible, however, it will then stay visible regardless of what is focussed/clicked on or if the mouse leaves the area of the dialog.

Reproduce

1. Open slimtrade
2. Close poe if it is open
3. Take note of menubar location
4. Mouse over menubar location
5. Move mouse away from menubar/click other window etc

Setting
SlimTrade Version: 0.5.0
Operation System: Win11

Additional context
In my opinion the menu bar should not be openable when poe is not the active window anyway since settings can be accessed from the taskbar therefore my preference would be for this functionality to be removed.

Part of the issue is that if the menubar is shown via the mouseover method and poe is not open the "show" state variable in VisibilityManager is not modified which prevents the global click listener from triggering the overlay to hide.

The showing/hiding mechanism in FrameManager doesn't seem to be working correctly either.

Note that if I click the cog, then close that window, clicking another window correctly hides the overlay.