vulkan: Implement VK_EXT_debug_utils
This extension is a superset of both VK_EXT_debug_report and VK_EXT_debug_marker. We should be able to implement this in 100% common code and it should be able to use the driver function as VK_EXT_debug_report to report errors and debug info to apps. We don't have any of the debug marker stuff yet but it shouldn't be hard to add, especially now that we have the common infrastructure. We may want to hook up VK_EXT_debug_marker at the same time just in case older apps want it.