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/LegacyXmlPublishedCache/LegacyBackgroundTask/ILatchedBackgroundTask.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Threading.Tasks;
+
+namespace Umbraco.Web.Scheduling
+{
+    /// <summary>
+    /// Represents a latched background task.
+    /// </summary>
+    /// <remarks>Latched background tasks can suspend their execution until
+    /// a condition is met. However if the tasks runner has to terminate,
+    /// latched background tasks can be executed immediately, depending on
+    /// the value returned by RunsOnShutdown.</remarks>
+    public interface ILatchedBackgroundTask : IBackgroundTask
+    {
+        /// <summary>
+        /// Gets a task on latch.
+        /// </summary>
+        /// <exception cref="InvalidOperationException">The task is not latched.</exception>
+        Task Latch { get; }
+
+        /// <summary>
+        /// Gets a value indicating whether the task is latched.
+        /// </summary>
+        /// <remarks>Should return false as soon as the condition is met.</remarks>
+        bool IsLatched { get; }
+
+        /// <summary>
+        ///  Gets a value indicating whether the task can be executed immediately if the task runner has to terminate.
+        /// </summary>
+        bool RunsOnShutdown { get; }
+    }
+}