Ability to copying authorization URL for Gmail (#375)

* Implemented copying auth URL for Gmail authentication.

* Update Button icon and add row spacing in Flyout grid

The icon used in the Button.Content has been updated to a new
design and is now wrapped inside a Viewbox with a width of 20
to ensure proper scaling. Additionally, the Grid inside the
Flyout now includes RowSpacing="12" to improve visual separation
between rows.

Wino.Mail/Dialogs/AccountCreationDialog.xaml.cs

@@ -1,15 +1,42 @@
-namespace Wino.Dialogs
+using System;
+using System.Threading.Tasks;
+using CommunityToolkit.Mvvm.Messaging;
+using Microsoft.Extensions.DependencyInjection;
+using Wino.Core.Domain.Interfaces;
+using Wino.Messaging.Server;
+
+namespace Wino.Dialogs
 {
-    public sealed partial class AccountCreationDialog : BaseAccountCreationDialog
+    public sealed partial class AccountCreationDialog : BaseAccountCreationDialog, IRecipient<CopyAuthURLRequested>
     {
+        private string copyClipboardURL;
         public AccountCreationDialog()
         {
             InitializeComponent();
+
+            WeakReferenceMessenger.Default.Register(this);
         }
 
-        private void CancelClicked(object sender, Windows.UI.Xaml.RoutedEventArgs e)
+        public async void Receive(CopyAuthURLRequested message)
         {
-            Complete(true);
+            copyClipboardURL = message.AuthURL;
+
+            await Task.Delay(2000);
+
+            await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
+            {
+                AuthHelpDialogButton.Visibility = Windows.UI.Xaml.Visibility.Visible;
+            });
+        }
+
+        private void CancelClicked(object sender, Windows.UI.Xaml.RoutedEventArgs e) => Complete(true);
+
+        private async void CopyClicked(object sender, Windows.UI.Xaml.RoutedEventArgs e)
+        {
+            if (string.IsNullOrEmpty(copyClipboardURL)) return;
+
+            var clipboardService = App.Current.Services.GetService<IClipboardService>();
+            await clipboardService.CopyClipboardAsync(copyClipboardURL);
         }
     }
 }