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.Messages/Server/AuthorizationRequested.cs

@@ -7,5 +7,5 @@ namespace Wino.Messaging.Server
     /// <summary>
     /// For delegating authentication/authorization to the server app.
     /// </summary>
-    public record AuthorizationRequested(MailProviderType MailProviderType, MailAccount CreatedAccount) : IClientMessage;
+    public record AuthorizationRequested(MailProviderType MailProviderType, MailAccount CreatedAccount, bool ProposeCopyAuthorizationURL) : IClientMessage;
 }