Fix and re-enable 3D failing feature tests. #51
Description
https://dev.azure.com/dnceng/internal/_git/dotnet-wpf-test/pullrequest/1739?_a=overview disables failing feature tests.
The following test case was disabled as it fails in .NET Core. it passes in .NET Framework:
/Name="Video - Basic Video on 3D - blue, green, red, 10 secs" /SubArea="BVT - Scenario"
The following were disabled only for Windows 8.1
/Name="Video - Basic Video on 3D" /SubArea="P2-Scenario"
The following were disabled only for Windows Server 2012
/Name="All BVTs (PerspectiveCamera) - FlowDirection=RightToLeft" /SubArea="P3"