MASA, OMASA, MC-paramupmix path functions and float code cleanup

[x] Conversion & Integration of fb_mixer related functions, ivas_fb_mixer_pcm_ingest_fx, ivas_mc_paramupmix_dmx, computeIntensityVector_enc_fx, differential_coding_first_subframe
[x] CPE-ENC cleanup
[x] Intermediate conversions in ivas_compute_core_buffers cleanup
[x] Convert functions in omasa_enc.c
[x] ivas_qmetadata_enc_encode path changes