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/Crayon/UI/CrayonWindow.xaml.cs

@@ -18,18 +18,17 @@ namespace Content.Client.Crayon.UI
     [GenerateTypedNameReferences]
     public sealed partial class CrayonWindow : DefaultWindow
     {
-        public CrayonBoundUserInterface Owner { get; }
-
         private Dictionary<string, Texture>? _decals;
         private string? _selected;
         private Color _color;
 
-        public CrayonWindow(CrayonBoundUserInterface owner)
+        public event Action<Color>? OnColorSelected;
+        public event Action<string>? OnSelected;
+
+        public CrayonWindow()
         {
             RobustXamlLoader.Load(this);
 
-            Owner = owner;
-
             Search.OnTextChanged += _ => RefreshList();
             ColorSelector.OnColorChanged += SelectColor;
         }
@@ -38,16 +37,16 @@ namespace Content.Client.Crayon.UI
         {
             _color = color;
 
-            Owner.SelectColor(color);
-
+            OnColorSelected?.Invoke(color);
             RefreshList();
         }
 
         private void RefreshList()
         {
             // Clear
-            Grid.RemoveAllChildren();
-            if (_decals == null) return;
+            Grid.DisposeAllChildren();
+            if (_decals == null)
+                return;
 
             var filter = Search.Text;
             foreach (var (decal, tex) in _decals)
@@ -89,7 +88,6 @@ namespace Content.Client.Crayon.UI
         {
             if (obj.Button.Name == null) return;
 
-            Owner.Select(obj.Button.Name);
             _selected = obj.Button.Name;
             RefreshList();
         }