Hide titlebar for clients that request so

Co-authored-by: Arkhist <peyrille.benjamin@gmail.com>

simple/init.lua

@@ -715,6 +715,10 @@ client.connect_signal("request::titlebars", function(c)
         },
         layout = wibox.layout.align.horizontal
     }
+
+    if c.requests_no_titlebar then
+        awful.titlebar.hide(c)
+    end
 end)
 
 -- Enable sloppy focus, so that focus follows mouse.