Implemented initial version for popping out window for rendering and compose pages

Wino.Mail.WinUI/Models/HostedPopoutDescriptor.cs

@@ -0,0 +1,10 @@
+namespace Wino.Mail.WinUI.Models;
+
+public sealed record HostedPopoutDescriptor(
+    string WindowName,
+    string Title,
+    double Width,
+    double Height,
+    double MinWidth,
+    double MinHeight,
+    string ContentKind);

Wino.Mail.WinUI/Models/PopOutRequestedEventArgs.cs

@@ -0,0 +1,8 @@
+using System;
+
+namespace Wino.Mail.WinUI.Models;
+
+public sealed class PopOutRequestedEventArgs : EventArgs
+{
+    public static PopOutRequestedEventArgs Default { get; } = new();
+}

Wino.Mail.WinUI/Models/PopoutHostActionKind.cs

@@ -0,0 +1,9 @@
+using System;
+
+namespace Wino.Mail.WinUI.Models;
+
+public enum PopoutHostActionKind
+{
+    CloseHostedInstance,
+    PopOutNextNavigation
+}

Wino.Mail.WinUI/Models/PopoutHostActionRequestedEventArgs.cs

@@ -0,0 +1,17 @@
+using System;
+
+namespace Wino.Mail.WinUI.Models;
+
+public sealed class PopoutHostActionRequestedEventArgs : EventArgs
+{
+    public PopoutHostActionRequestedEventArgs(PopoutHostActionKind actionKind, Type? targetPageType = null, Guid? targetMailUniqueId = null)
+    {
+        ActionKind = actionKind;
+        TargetPageType = targetPageType;
+        TargetMailUniqueId = targetMailUniqueId;
+    }
+
+    public PopoutHostActionKind ActionKind { get; }
+    public Type? TargetPageType { get; }
+    public Guid? TargetMailUniqueId { get; }
+}

Wino.Mail.WinUI/Models/WinoWindowKind.cs

@@ -3,5 +3,6 @@ namespace Wino.Mail.WinUI.Models;
 public enum WinoWindowKind
 {
     Shell,
-    Welcome
+    Welcome,
+    HostedPopout
 }