Add utl::profiler

Single-header profiler for C++17, uses a rather unique approach useful for constrained environments. - [Link to the documentation](https://github.com/DmitriBogdanov/UTL/blob/master/docs/module_profiler.md) - [Link to the header](https://github.com/DmitriBogdanov/UTL/blob/master/include/UTL/profiler.hpp) - [Link to the repo](https://github.com/DmitriBogdanov/UTL) There are some other libs managed under the same repo, but this is simply a convenience choice, all libraries are independent.