improve polar init and polar readability
make some improvements in CPU intensive parts of nr_polar_params() as this function kills the real time when it is called
remove quite a lot of malloc, for stack usage
remove dead pieces of code in polar codec
make general C better: use the 64bits CPU as it should (remove force to int8 when useless)
make indentation according to OAI style
fix minor race cond (mutex was freed then modify chained list)
this MR is likely a intermediate step in deeper polar codec cleaning