Add tests for the VK_KHR_16bit_storage extension

Add tests for the VK_KHR_16bit_storage extension

* Four capabilities
  * StorageUniform16
  * StorageUniformBufferBlock16
  * StorageInputOutput16
  * StoragePushConstant16
* 16bit -> 32bit and 32bit -> 16bit
* integers and floats
* vectors and matrices of integers and floats

Component: Vulkan

(cherry picked from commit e62c7b595cbf79617555faf46eb9085bb7d11cb1)

Contains following two follow-up patches:
 * d41f0578749db200124a933a0bc6ace35881d02d (check against linea/optimalTilingFeatures)
 * a24bed1ac5b06e6ef87da3b6f9bc103f5cdf463f (allow flusing denormals)
 * ff75accb8c0634ddfa920462d864a58f12a76198 (add missing extensions)

Change-Id: I51f59d9a7d984f5190c8d60752454b963a039c2e