vkCreateDevice doesn't check features against enabled extensions

Moved from https://github.com/KhronosGroup/Vulkan-ValidationLayers/issues/2818

To sum up the issue:

```cpp
VkPhysicalDevice16BitStorageFeaturesKHR ext_feature = {};

VkPhysicalDeviceFeatures2 physical_features2 = {};
physical_features2.pNext = &ext_feature;

// Assume VK_KHR_get_physical_device_properties2 enabled at instance level
vkGetPhysicalDeviceFeatures2(physical_device, &physical_features2);

assert(ext_feature.storagePushConstant16 == VK_TRUE);

VkDeviceCreateInfo device_info = {};
device_info.pNext = &physical_features2;
device_info.enabledExtensionCount = 0; // VK_KHR_16bit_storage NOT enabled
vkCreateDevice(&device_info);
```

In the case of a 1.0 Vulkan implementation, there seems to be no explicit VU saying

> If you enable the supported feature, the device version must support it OR the device extension must enable it

@rua pointed to spots in the spec, but currently the Validation Layers are not checking for this