Netcore: Align namespaces (#9801)

* Rename Umbraco.Core namespace to Umbraco.Cms.Core

* Move extension methods in core project to Umbraco.Extensions

* Move extension methods in core project to Umbraco.Extensions

* Rename Umbraco.Examine namespace to Umbraco.Cms.Examine

* Move examine extensions to Umbraco.Extensions namespace

* Reflect changed namespaces in Builder and fix unit tests

* Adjust namespace in Umbraco.ModelsBuilder.Embedded

* Adjust namespace in Umbraco.Persistence.SqlCe

* Adjust namespace in Umbraco.PublishedCache.NuCache

* Align namespaces in Umbraco.Web.BackOffice

* Align namespaces in Umbraco.Web.Common

* Ensure that SqlCeSupport is still enabled after changing the namespace

* Align namespaces in Umbraco.Web.Website

* Align namespaces in Umbraco.Web.UI.NetCore

* Align namespaces in Umbraco.Tests.Common

* Align namespaces in Umbraco.Tests.UnitTests

* Align namespaces in Umbraco.Tests.Integration

* Fix errors caused by changed namespaces

* Fix integration tests

* Undo the Umbraco.Examine.Lucene namespace change

This breaks integration tests on linux, since the namespace wont exists there because it's only used on windows.

* Fix merge

* Fix Merge

src/Umbraco.Core/Models/HaveAdditionalDataExtensions.cs

@@ -0,0 +1,20 @@
+// Copyright (c) Umbraco.
+// See LICENSE for more details.
+
+using Umbraco.Cms.Core.Models.Entities;
+
+namespace Umbraco.Extensions
+{
+    public static class HaveAdditionalDataExtensions
+    {
+        /// <summary>
+        /// Gets additional data.
+        /// </summary>
+        public static object GetAdditionalDataValueIgnoreCase(this IHaveAdditionalData entity, string key, object defaultValue)
+        {
+            if (!entity.HasAdditionalData) return defaultValue;
+            if (entity.AdditionalData.ContainsKeyIgnoreCase(key) == false) return defaultValue;
+            return entity.AdditionalData.GetValueIgnoreCase(key, defaultValue);
+        }
+    }
+}