Workaround for this: when opening a context menu at cursor position,
cursor will be in the menu's border instead of first menu item,
forcing the user to move the mouse for the click to do anything.
Introduce a HmenuItemPopupSpawner component that takes care of reacting
to onTriggered signals and calling the utils.makePopup() function.
The combination of this new component used in HMenu to open a HPopup
now correctly takes and restore focus to the right element when closed.