Create a dedicated stress test file and executable

[spencer-lunarg]

Currently for Sync Val and GPU we have things like CopyPagesInSmallChunks and

// Disabled as this is a perf testing test, not much value in normal CI
TEST_F(PositiveGpuAVDescriptorIndexing, DISABLED_Stress) {

that really don't make sense

The idea is to

• create a sync_val_stress.cpp and gpu_av_stress.cpp file
• rename tests to StressGpuAV, SomeName
• Create a vk_layer_validation_tests.exe and vk_layer_validation_stress.exe so that both can be ran whenever we want, but also the current CI run using vk_layer_validation_tests.exe will not have to spend time on it

started idea over here https://github.com/spencer-lunarg/Vulkan-ValidationLayers/tree/spencer-lunarg-stress-test