Move test projects from src/ to tests/ (#11357)

* Update gitignore

* Move csproj

* Update project references

* Update solutions

* Update build scripts

* Tests used to share editorconfig with projects in src

* Fix broken tests.

* Stop copying around .editorconfig

merged root one with linting

* csharp_style_expression_bodied -> suggestion

* Move StyleCop rulesets to matching directories and update shared build properties

* Remove legacy build files, update NuGet.cofig and solution files

* Restore myget source

* Clean up .gitignore

* Update .gitignore

* Move new test classes to tests after merge

* Gitignore + nuget config

* Move new test

Co-authored-by: Ronald Barendse <ronald@barend.se>

tests/Umbraco.Tests.UnitTests/Umbraco.Core/Models/DocumentEntityTests.cs

@@ -0,0 +1,46 @@
+// Copyright (c) Umbraco.
+// See LICENSE for more details.
+
+using System.Diagnostics;
+using Newtonsoft.Json;
+using NUnit.Framework;
+using Umbraco.Cms.Core.Models.Entities;
+using Umbraco.Cms.Tests.Common.Builders;
+using Umbraco.Cms.Tests.Common.Builders.Extensions;
+
+namespace Umbraco.Cms.Tests.UnitTests.Umbraco.Core.Models
+{
+    [TestFixture]
+    public class DocumentEntityTests
+    {
+        private DocumentEntitySlimBuilder _builder;
+
+        [SetUp]
+        public void SetUp() => _builder = new DocumentEntitySlimBuilder();
+
+        [Test]
+        public void Can_Serialize_Without_Error()
+        {
+            DocumentEntitySlim item = _builder
+                .WithId(3)
+                .WithCreatorId(4)
+                .WithName("Test")
+                .WithParentId(5)
+                .WithSortOrder(6)
+                .WithLevel(7)
+                .WithContentTypeAlias("test1")
+                .WithContentTypeIcon("icon")
+                .WithContentTypeThumbnail("thumb")
+                .WithHasChildren(true)
+                .WithPublished(true)
+                .AddAdditionalData()
+                    .WithKeyValue("test1", 3)
+                    .WithKeyValue("test2", "value")
+                    .Done()
+                .Build();
+
+            var json = JsonConvert.SerializeObject(item);
+            Debug.Print(json);
+        }
+    }
+}