Revert "File scoped namespaces"

This reverts commit d31d8f574e.

Wino.Core.Domain/Models/MailItem/IMailHashContainer.cs

@@ -1,14 +1,15 @@
 using System;
 using System.Collections.Generic;
 
-namespace Wino.Core.Domain.Models.MailItem;
-
-/// <summary>
-/// An interface that returns the UniqueId store for IMailItem.
-/// For threads, it may be multiple items.
-/// For single mails, it'll always be one item.
-/// </summary>
-public interface IMailHashContainer
+namespace Wino.Core.Domain.Models.MailItem
 {
-    IEnumerable<Guid> GetContainingIds();
+    /// <summary>
+    /// An interface that returns the UniqueId store for IMailItem.
+    /// For threads, it may be multiple items.
+    /// For single mails, it'll always be one item.
+    /// </summary>
+    public interface IMailHashContainer
+    {
+        IEnumerable<Guid> GetContainingIds();
+    }
 }