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.Server/ServerContext.cs

@@ -42,7 +42,8 @@ namespace Wino.Server
         IRecipient<RefreshUnreadCountsMessage>,
         IRecipient<ServerTerminationModeChanged>,
         IRecipient<AccountSynchronizationProgressUpdatedMessage>,
-        IRecipient<AccountFolderConfigurationUpdated>
+        IRecipient<AccountFolderConfigurationUpdated>,
+        IRecipient<CopyAuthURLRequested>
     {
         private readonly System.Timers.Timer _timer;
         private static object connectionLock = new object();
@@ -139,6 +140,8 @@ namespace Wino.Server
 
         public async void Receive(AccountFolderConfigurationUpdated message) => await SendMessageAsync(MessageType.UIMessage, message);
 
+        public async void Receive(CopyAuthURLRequested message) => await SendMessageAsync(MessageType.UIMessage, message);
+
         #endregion
 
         private string GetAppPackagFamilyName()