wayland/toplevel: Don't alwyas skip changing xdg_toplevel state

We only called xdg_toplevel.(un)set_maximize() if the toplevel layout
changed, but this misses the case when the compositor had changed the
maximized state. Change it to call the xdg_toplevel request if either
the local layout changed, or if the layout differs from the current
state.

This fixes an issue where one couldn't unmaximize a window by double
clicking the titlebar that, had previously been maximized e.g. using a
keyboard binding.

Do the same for fullscreen.

gdk/wayland/gdksurface-wayland.c

@@ -4876,6 +4876,8 @@ did_maximize_layout_change (GdkToplevel       *toplevel,
     return TRUE;
 
   if (gdk_toplevel_layout_get_maximized (impl->toplevel.layout) !=
+      gdk_toplevel_layout_get_maximized (layout) ||
+      !!(surface->state & GDK_TOPLEVEL_STATE_MAXIMIZED) !=
       gdk_toplevel_layout_get_maximized (layout))
     return TRUE;
 
@@ -4893,6 +4895,8 @@ did_fullscreen_layout_change (GdkToplevel       *toplevel,
     return TRUE;
 
   if (gdk_toplevel_layout_get_fullscreen (impl->toplevel.layout) !=
+      gdk_toplevel_layout_get_fullscreen (layout) ||
+      !!(surface->state & GDK_TOPLEVEL_STATE_FULLSCREEN) !=
       gdk_toplevel_layout_get_fullscreen (layout))
     return TRUE;