Ground work for Wino Calendar. (#475)

Wino Calendar abstractions.

Wino.Core.UWP/Extensions/UIExtensions.cs

@@ -0,0 +1,20 @@
+using Microsoft.UI.Xaml.Controls;
+using Wino.Core.Domain.Enums;
+
+namespace Wino.Extensions
+{
+    public static class UIExtensions
+    {
+        public static InfoBarSeverity AsMUXCInfoBarSeverity(this InfoBarMessageType messageType)
+        {
+            return messageType switch
+            {
+                InfoBarMessageType.Error => InfoBarSeverity.Error,
+                InfoBarMessageType.Warning => InfoBarSeverity.Warning,
+                InfoBarMessageType.Information => InfoBarSeverity.Informational,
+                InfoBarMessageType.Success => InfoBarSeverity.Success,
+                _ => InfoBarSeverity.Informational
+            };
+        }
+    }
+}