Fix some compilation warnings (#1010)

* Fixe some summary warning

* Fixed more warning

* Uniformed example projects code

* Uniformed test projects code

* Fix OperatingSystems enum and GenericType summaries

tests/KubernetesClient.Tests/ExternalExecutionTests.cs

@@ -1,6 +1,6 @@
+using k8s.KubeConfigModels;
 using System.Collections.Generic;
 using System.Text.Json;
-using k8s.KubeConfigModels;
 using Xunit;
 
 namespace k8s.Tests