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/Paper/UI/PaperBoundUserInterface.cs

@@ -1,4 +1,5 @@
 using JetBrains.Annotations;
+using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;
 using Robust.Shared.Utility;
 using static Content.Shared.Paper.SharedPaperComponent;
@@ -19,16 +20,13 @@ public sealed class PaperBoundUserInterface : BoundUserInterface
     {
         base.Open();
 
-        _window = new PaperWindow();
-        _window.OnClose += Close;
-        _window.OnSaved += Input_OnTextEntered;
+        _window = this.CreateWindow<PaperWindow>();
+        _window.OnSaved += InputOnTextEntered;
 
         if (EntMan.TryGetComponent<PaperVisualsComponent>(Owner, out var visuals))
         {
             _window.InitVisuals(Owner, visuals);
         }
-
-        _window.OpenCentered();
     }
 
     protected override void UpdateState(BoundUserInterfaceState state)
@@ -37,7 +35,7 @@ public sealed class PaperBoundUserInterface : BoundUserInterface
         _window?.Populate((PaperBoundUserInterfaceState) state);
     }
 
-    private void Input_OnTextEntered(string text)
+    private void InputOnTextEntered(string text)
     {
         SendMessage(new PaperInputTextMessage(text));
 
@@ -47,11 +45,4 @@ public sealed class PaperBoundUserInterface : BoundUserInterface
             _window.Input.CursorPosition = new TextEdit.CursorPos(0, TextEdit.LineBreakBias.Top);
         }
     }
-
-    protected override void Dispose(bool disposing)
-    {
-        base.Dispose(disposing);
-        if (!disposing) return;
-        _window?.Dispose();
-    }
 }