Quantization Polish

Description

This merge request aims to enhance drastically the quantization module, by reworking the code, documenting it, and fixing a critical bug. The new code should allow to run the quantization tutorial on multibranch architectures. Here is a list of the provided changes:

• Simplify the handling of residual branches
• Fix a critical bug in the quantization algorithm
• Clean the headers and includes
• Replace the 'cout' logs by 'fmt' ones
• Add the doxygen documentation in the header
• Add the sphinx docstrings in the pybind
• Fix the import of fmt in the CMake
• Update the Readme.md

Modified files : QuantPTQ.hpp, QuantPTQ.cpp, pybind_QuantPTQ.cpp, CMakeLists.txt and Readme.md