github: add double-click to select behaviour to select account

Add the ability to double-click to select an account and 'continue' for
the account selection Avalonia window.

Author: mjcheetham

src/shared/GitHub/UI/Views/SelectAccountView.axaml

@@ -48,7 +48,8 @@
                      Margin="20,0,20,10"
                      MaxHeight="200"
                      Background="Transparent"
-                     AutoScrollToSelectedItem="True">
+                     AutoScrollToSelectedItem="True"
+                     DoubleTapped="ListBox_OnDoubleTapped">
                 <ListBox.ItemTemplate>
                     <DataTemplate DataType="vm:AccountViewModel">
                         <DockPanel LastChildFill="True">

src/shared/GitHub/UI/Views/SelectAccountView.axaml.cs

@@ -1,6 +1,8 @@
 using Avalonia;
 using Avalonia.Controls;
+using Avalonia.Input;
 using Avalonia.Markup.Xaml;
+using GitHub.UI.ViewModels;
 
 namespace GitHub.UI.Views;
 
@@ -15,4 +17,12 @@ private void InitializeComponent()
     {
         AvaloniaXamlLoader.Load(this);
     }
+
+    private void ListBox_OnDoubleTapped(object sender, TappedEventArgs e)
+    {
+        if (DataContext is SelectAccountViewModel { SelectedAccount: not null } vm)
+        {
+            vm.ContinueCommand.Execute(null);
+        }
+    }
 }