Add tests for VK_EXT_provoking_vertex

Add tests for VK_EXT_provoking_vertex

Replace VkScript-based provoking vertex tests with one file that tests
both the default Vulkan provoking vertex convention and different
provoking vertex modes provided by VK_EXT_provoking_vertex.

New tests:
dEQP-VK.rasterization.provoking_vertex.default.*
dEQP-VK.rasterization.provoking_vertex.first.*
dEQP-VK.rasterization.provoking_vertex.last.*
dEQP-VK.rasterization.provoking_vertex.per_pipeline.*

Affects:
dEQP-VK.rasterization.provoking_vertex.*

Components: Vulkan

VK-GL-CTS issue: 2092

Change-Id: I472c8c15ca1c0ad51a2dcc16ef9fa3d5f6ba5fa7
(cherry picked from commit 2d23e0e1a180c4dc8b5bcde8a4713527b7ef50b9)