Remove some BUI boilerplate (#28399)

* Remove some BUI boilerplate

- The disposals overrides got removed due to the helper method handling it.
- Replace window creation with CreateWindow helper.
- Fixed some stinky code which would cause exceptions.

* More

* moar

* weh

* done

* More BUIs

* More updates

* weh

* moar

* look who it is

* weh

* merge

* weh

* fixes

Content.Client/PDA/Ringer/RingerBoundUserInterface.cs

@@ -1,6 +1,7 @@
 using Content.Shared.PDA;
 using Content.Shared.PDA.Ringer;
 using JetBrains.Annotations;
+using Robust.Client.UserInterface;
 using Robust.Shared.Timing;
 
 namespace Content.Client.PDA.Ringer
@@ -18,9 +19,8 @@ namespace Content.Client.PDA.Ringer
         protected override void Open()
         {
             base.Open();
-            _menu = new RingtoneMenu();
+            _menu = this.CreateWindow<RingtoneMenu>();
             _menu.OpenToLeft();
-            _menu.OnClose += Close;
 
             _menu.TestRingerButton.OnPressed += _ =>
             {