Fix namespaces when building MB models

src/Umbraco.Core/Dashboards/ModelsBuilderDashboard.cs

@@ -0,0 +1,17 @@
+using System;
+using Umbraco.Cms.Core.Composing;
+
+namespace Umbraco.Cms.Core.Dashboards
+{
+    [Weight(40)]
+    public class ModelsBuilderDashboard : IDashboard
+    {
+        public string Alias => "settingsModelsBuilder";
+
+        public string[] Sections => new [] { "settings" };
+
+        public string View => "views/dashboard/settings/modelsbuildermanagement.html";
+
+        public IAccessRule[] AccessRules => Array.Empty<IAccessRule>();
+    }
+}