wayland: Use pop shell type for all transient style of surfaces

It's easy to test this functionality by opening a sub-window (e.g. right click
on the Web content), and without closing it go outside the Chromium window and
hover the mouse cursor over another Wayland application. Now, none interaction
using the mouse pointer should happen on those applications unless you click
again. IWO input grabbing across applications now are alright because Wayland
does it implicitly.
wayland: Implement HandlePopupDone callback for dispatching close window

Now if a menu is opened and the user clicks outside a Chromium window then the
popup done event will dispatch a close window for that menu.

--single-process behaves like expected but when in multi-processed, the menu
destruction sometimes is delayed until there's input happening again. It's a
bug that needs to be fixed still.