Add support for OpenGL interop to Dax.

We are adding a new opengl namespace with functions that will
take an array handle and transfer its contents to a given opengl
buffer.
Add testing infrastructure to verify opengl interop works.

We need to really test the interop code with all device adapters
to verify that it works under all uses cases. To do that I am
adding infrastructure that makes it easy to test the interop
Add in benchmark that tests the openGL interop performance.

The test verifies that the interop can handle being push a couple
million triangles and still get a good fps.