"Fix StyleCop violations" removes "using static"

When i run _Cleanup Code_ with _Fix StyleCop violations_ enabled all `using static directives` are converted into normal `using directives`, resulting in compile errors.

 ```csharp
namespace MyNamespace
{
    using static ClassWithStaticMethods;
 ```

becomes

 ```csharp
namespace MyNamespace
{
    using ClassWithStaticMethods;
 ```
