Add Windows share target draft attachment flow

Wino.Core.Domain/Models/Launch/MailShareRequest.cs

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+using System;
+using System.Collections.Generic;
+using Wino.Core.Domain.Models.Common;
+
+namespace Wino.Core.Domain.Models.Launch;
+
+public sealed class MailShareRequest
+{
+    public MailShareRequest(IReadOnlyList<SharedFile> files)
+    {
+        Files = files ?? throw new ArgumentNullException(nameof(files));
+    }
+
+    public IReadOnlyList<SharedFile> Files { get; }
+}

Wino.Core.Domain/Models/Launch/PendingComposeMailShareRequest.cs

@@ -0,0 +1,15 @@
+using System;
+
+namespace Wino.Core.Domain.Models.Launch;
+
+public sealed class PendingComposeMailShareRequest
+{
+    public PendingComposeMailShareRequest(Guid draftUniqueId, MailShareRequest shareRequest)
+    {
+        DraftUniqueId = draftUniqueId;
+        ShareRequest = shareRequest ?? throw new ArgumentNullException(nameof(shareRequest));
+    }
+
+    public Guid DraftUniqueId { get; }
+    public MailShareRequest ShareRequest { get; }
+}