Online Search (#576)

* Very basic online search for gmail.

* Server side of handling offline search and listing part in listing page.

* Default search mode implementation and search UI improvements.

* Online search for Outlook.

* Very basic online search for gmail.

* Server side of handling offline search and listing part in listing page.

* Default search mode implementation and search UI improvements.

* Online search for Outlook.

* Online search for imap without downloading the messages yet. TODO

* Completing imap search.

Wino.Server/MessageHandlers/OnlineSearchRequestHandler.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Wino.Core.Domain.Interfaces;
+using Wino.Core.Domain.Models.Server;
+using Wino.Core.Domain.Models.Synchronization;
+using Wino.Messaging.Server;
+using Wino.Server.Core;
+
+namespace Wino.Server.MessageHandlers;
+
+public class OnlineSearchRequestHandler : ServerMessageHandler<OnlineSearchRequested, OnlineSearchResult>
+{
+    private readonly ISynchronizerFactory _synchronizerFactory;
+
+    public OnlineSearchRequestHandler(ISynchronizerFactory synchronizerFactory)
+    {
+        _synchronizerFactory = synchronizerFactory;
+    }
+
+    public override WinoServerResponse<OnlineSearchResult> FailureDefaultResponse(Exception ex)
+            => WinoServerResponse<OnlineSearchResult>.CreateErrorResponse(ex.Message);
+
+    protected override async Task<WinoServerResponse<OnlineSearchResult>> HandleAsync(OnlineSearchRequested message, CancellationToken cancellationToken = default)
+    {
+        List<IWinoSynchronizerBase> synchronizers = new();
+
+        foreach (var accountId in message.AccountIds)
+        {
+            var synchronizer = await _synchronizerFactory.GetAccountSynchronizerAsync(accountId);
+            synchronizers.Add(synchronizer);
+        }
+
+        var tasks = synchronizers.Select(s => s.OnlineSearchAsync(message.QueryText, message.Folders, cancellationToken)).ToList();
+        var results = await Task.WhenAll(tasks);
+
+        // Flatten the results from all synchronizers into a single list
+        var allResults = results.SelectMany(x => x).ToList();
+
+        return WinoServerResponse<OnlineSearchResult>.CreateSuccessResponse(new OnlineSearchResult(allResults));
+    }
+}