Feature request: API dump actual thread id as well

[wasimabbas-arm]

Currently API dump will save thread ids into a std::map and return index of the thread id in the map which is a sequential number from 0 to something. https://github.com/LunarG/VulkanTools/blob/1ea8d1602741d22f73d3b39c5c78eed86897da04/layersvt/api_dump.h#L859

This looks good but unusable. I can't compare this to the actual thread IDs I get in my application that I get via std::this_thread::get_id()

Ideally threadID() could return a pair of actual thread id as string and the map incremental id so both can be displayed.