Test several performance improvements

[Gabriel-p]

• Separate binary photometry into a different array
• Calculate searchsorted indices between mass_init and mass_dist (sampled from the IMF) when instantiating the synthetic class
• Move masses (primary + secondary) arrays to the beginning of the theoretical_isochrones array
• Add stars (interpolate) during the binary generation, generate binaries and then remove to go back to the old number of stars (maybe helps with low-mass artifacts?)