Fixes #4022 file dialog tests and bugfix for cancellation (#4024)

* Add class for detecting information about console in extensible way

* WIP - Create test for reordering

* Change Dictionary to List and preserve TreeBuilder order

* Add test to ensure branch expansion/status remains consistent despite reorder

* Cleanup code

* Fix regression when removed child was the selected one

* Revert "Add class for detecting information about console in extensible way"

This reverts commit 7e4253cf28.

* Code cleanup and enable nullable on Branch

* Remove color scheme and driver from Branch draw

* Add xunit context extensions

* Investigate codegen for xunit

* Getting closer to something that works

* Fix code generation

* Further explore code gen

* Generate all methods in single class for easier extensibility

* Simplify code gen by moving parameter creation to its own method

* Implement asserts A-I

* Add remaining assert calls that are not obsolete

* Fix unit test

* Roll back versions to be compatible with CI version of csharp

* Handle params and ref etc

* Fix null warning

* WIP - start to add integration tests for FileDialog

* Add ability to tab focus to specific control with simple one line delegate

* Clarify test criteria

* Add unit tests for Ok and other ways of canceling dialog

* Fix other buttons also triggering save

* Fix for linux environment tests

* Fix for linux again

* Fix application null race condition - add better way of knowing if stuff is finished

* Better fix for shutdown detection

* Add test that shows #4026 is not an issue

* Switch to `_fileSystem.Directory.GetLogicalDrives ()`

* Don't show duplicate MyDocuments etc

Tests/IntegrationTests/IntegrationTests.csproj

@@ -26,7 +26,7 @@
     </ItemGroup>
     <ItemGroup>
         <ProjectReference Include="..\..\Terminal.Gui\Terminal.Gui.csproj" />
-        <ProjectReference Include="..\..\TerminalGuiFluentTesting.Xunit\TerminalGuiFluentTesting.Xunit.csproj" />
+        <ProjectReference Include="..\..\TerminalGuiFluentTestingXunit\TerminalGuiFluentTestingXunit.csproj" />
         <ProjectReference Include="..\..\TerminalGuiFluentTesting\TerminalGuiFluentTesting.csproj" />
         <ProjectReference Include="..\..\UICatalog\UICatalog.csproj" />
         <ProjectReference Include="..\UnitTests\UnitTests.csproj" />