Few functions in ivas_masa_com converted to fixed point.

[x] quantize_theta_masa, inde_theta_phi_16, quantize_phi_masa functions converted to fixed point.

pytest results: 358 failed, 227 passed, 381 skipped

MLD:
Original: 7 cases > 5
8.623271 9.196089 9.304973 10.832478 10.853292 12.952374 22.458605

+10dB: 21 cases > 5
5.371162 5.505808 5.577011 5.663041 5.663041 6.287786 6.327793 6.992575 7.858168 10.755767 10.755767 11.334802 14.898525 16.603626 16.975687 19.353098 19.374039 19.761044 23.581322 27.03828 38.923706

-10dB: 5 cases > 5
5.965 6.009636 8.7374 15.85026 24.995966