taking into consideration variations across MTLDevice Features Sets.
Simplify contents and names in MVKMTLFmtCaps enum.
Add MVKVkFormatFeatureFlags enum to map capabilities from MVKMTLFmtCaps to VkFormat.
Derive three VkFormatFeatureFlags in VkFormatProperties from documented
MTLPixelFormat capabilities, customizing based on MTLDevice feature sets.
Include VK_FORMAT_FEATURE_STORAGE_IMAGE_ATOMIC_BIT and
VK_FORMAT_FEATURE_STORAGE_TEXEL_BUFFER_ATOMIC_BIT in writable features.
MVKPixelFormats modify VkFormatProperties unit test to log differences.
0c03f09df3