Fix how versions are handled in the test suite

[spencer-lunarg]

https://github.com/KhronosGroup/Vulkan-ValidationLayers/commit/6db385a7ea2c85d384df3e9ccff06729f71b22e9#diff-eefbaf049195ad7b10928b277b434137d20dbbd7654d1d6bc278f689b8a5a612R318

changed how the tests handled versions, previously one could write a test case that requires descriptor indexing to work with either core or extension as follows:

SetTargetApiVersion(VK_API_VERSION_1_3);
AddOptionalExtensions(VK_EXT_DESCRIPTOR_INDEXING_EXTENSION_NAME);
AddRequiredFeature(vkt::Feature::descriptorIndexing);

but now we have turned the SetTargetApiVersion into "require at least this version" syntax instead of using the old DeviceValidationVersion API

This will likely reflect on the test coverage the min_core.json profile that is being skipped

Need to have a better system to allow a larger test coverage with regards to versions