Speed up coh_tmm in tmm_core_vec; introduced versions with cpu and gpu parallelization

[arsonwong]

s and p polarization, 10000 wavelength x angles, 6 layers, calculate coh_tmm: before speed increase: 4.178s after speed increase: 2.399s after speed increase, non-detailed mode: 1.948s CPU parallelization with 24 cores CPU parallelization: 0.844s CPU parallelization, non-detailed mode: 0.719s GPU parallelization with NVIDIA GeForce RTX 4060 GPU parallelization: 0.296s GPU parallelization, non-detailed mode: 0.118s