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/MessageHandlers/AuthenticationHandler.cs

@@ -21,10 +21,21 @@ namespace Wino.Server.MessageHandlers
             _authenticationProvider = authenticationProvider;
         }
 
-        protected override async Task<WinoServerResponse<TokenInformation>> HandleAsync(AuthorizationRequested message, CancellationToken cancellationToken = default)
+        protected override async Task<WinoServerResponse<TokenInformation>> HandleAsync(AuthorizationRequested message,
+                                                                                        CancellationToken cancellationToken = default)
         {
             var authenticator = _authenticationProvider.GetAuthenticator(message.MailProviderType);
 
+            // Some users are having issues with Gmail authentication.
+            // Their browsers may never launch to complete authentication.
+            // Offer to copy auth url for them to complete it manually.
+            // Redirection will occur to the app and the token will be saved.
+
+            if (message.ProposeCopyAuthorizationURL && authenticator is IGmailAuthenticator gmailAuthenticator)
+            {
+                gmailAuthenticator.ProposeCopyAuthURL = true;
+            }
+
             // Do not save the token here. Call is coming from account creation and things are atomic there.
             var generatedToken = await authenticator.GenerateTokenAsync(message.CreatedAccount, saveToken: false);
 

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()