- Add MVKDeviceFeatureStructs.def file to describe each device feature
struct, and define, populate, and manage MVKDevice device feature
tracking iVars using the list in this file.
- Reorder switch cases in MVKPhysicalDevice::getFeatures() to match the
list in MVKDeviceFeatureStructs.def.
- Where possible, remove extension suffixes from device feature structs
and associated VkStructureType values.
- Remove const qualifier from device feature enabling structs.