New, saner, api

This version improves the api: mie.efficiencies() instead of mie.ez_mie() to find the Mie efficiencies. The source code has been refactored so there is less redundancy between jitted and non-jitted code. Other changes include

• breaking api changes
• use core.py to cleanly separate jit and non-jit code
• new function to calculate mie coefficients inside sphere
• new function to calculate E-fields near and far from sphere (only validated in far-field)
• new rayleigh.py
• new vsh.py to calculate vector spherical harmonics
• new util.py for printing complex numbers
• new bessel.py for complete spherical bessel function support
• new monte_carlo.py to isolate Monte Carlo routines
• use black for python formatting
• update all notebooks to use new api
• add more tests