Fix null Content.Name binding errors

src/UniGetUI.Avalonia/Assets/Styles/Styles.Common.axaml

@@ -1,6 +1,7 @@
 <Styles xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:controls="using:UniGetUI.Avalonia.Views.Controls"
+        xmlns:conv="using:UniGetUI.Avalonia.Converters"
         xmlns:settings="using:UniGetUI.Avalonia.Views.Controls.Settings"
         xmlns:primitives="using:Avalonia.Controls.Primitives"
         xmlns:automation="clr-namespace:Avalonia.Automation;assembly=Avalonia.Controls">
@@ -671,7 +672,7 @@
     </Style>
 
     <Style Selector="DataGridCell">
-        <Setter Property="automation:AutomationProperties.Name" Value="{Binding $self.((Control)Content).(automation:AutomationProperties.Name)}"/>
+        <Setter Property="automation:AutomationProperties.Name" Value="{Binding $self.Content, Converter={x:Static conv:AutomationNameOfContentConverter.Instance}}"/>
     </Style>
 
     <Style Selector="RadioButton:checked /template/ Ellipse#CheckOuterEllipse">

src/UniGetUI.Avalonia/Converters/AutomationNameOfContentConverter.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Globalization;
+using Avalonia.Automation;
+using Avalonia.Controls;
+using Avalonia.Data;
+using Avalonia.Data.Converters;
+
+namespace UniGetUI.Avalonia.Converters;
+
+/// <summary>
+/// Reads AutomationProperties.Name from a cell's content, tolerating the null content that
+/// virtualized DataGrid cells have while they are recycled.
+/// </summary>
+public sealed class AutomationNameOfContentConverter : IValueConverter
+{
+    public static readonly AutomationNameOfContentConverter Instance = new();
+
+    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+        => value is Control control
+            ? AutomationProperties.GetName(control)
+            : BindingOperations.DoNothing;
+
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+        => throw new NotSupportedException();
+}