Bgfx-python

Changelog:
* Updated BGFX version
* Fixed runtime header discovery

* Removed PyBind11 in favour of Cppyy, providing true automated code wrapping.
* Complete rewrite of the build system.
* Fixed Windows support over Visual Studio 2017.
* Code cleanup and performance fixes.

Changelog:
* Improved ImGui coverage

Changelog:
- Updated BGFX dependencies
- Added mesh loading utilities

Changelog:
* Fixed Windows shaders compilation
* Uses Poetry and Nox for project management
* Fixed Linux's Wheels size

Small refactorings.