* Changed the namespace for all the issues to Xamarin.Forms.Controls.Issues
* Moved some classes to Control directory with namespace Xamarin.Forms.Controls to fix conflicts after namespaces changes
* Fixed missed namespace for ButtonExtension
* Fixed namespace reference of Bugzilla42602 in WindowsUniversal/CustomRenderers.cs
* Creating a category just for core UI tests
* Grouping all of the core UI tests
* Adjusting categories so we can run in smaller batches
* Adding some of the Issues tests to categories
* Fix shared project nonsense
* Fix non-existent test category
* Testing global category for Issues