patch 9.2.0590: GTK4: drawing area loses focus shape on popup menu open

patch 9.2.0590: GTK4: drawing area loses focus shape on popup menu open

Problem:  GTK4: any focus change on the drawarea turns the cursor
          into an outline, including transient focus movement to a
          GUI popup menu and back.  The cursor flashes outline-shape
          during menu interaction.  The GTK3 GUI does not have this
          problem because it ties the cursor shape to toplevel window
          focus, not drawarea focus.
Solution: Gate focus_in_event() and focus_out_event() on
          gtk_window_is_active() of the toplevel window, matching
          GTK3 behaviour. Reverts v9.2.0588 (Foxe Chen).

closes: #20415

Signed-off-by: Foxe Chen <chen.foxe@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>