Core coder functions: acelp_core, stere_tcx_core and other sub-functions

[x] cng exc syn12k8, cng energy integration
[x] wb_tbe_extras_reset, InitSWBencBufferStates, swb_tbe_reset, TBEreset_enc, fb_tbe_reset_enc integration
[x] Converted kernel_switch_update_transforms function and its subfunctions in ivas_mdct_core_whitening_enc() call stack
[x] ivas_decision_matrix_enc and sub-functions converted and integrated
[x] Ported encod_gen2sbfr and its sub functions
[x] FEC_encode, non_linearity, updt_enc, cng_params_upd integration
[x] Converted QuantizeSpectrum and InternalTCXDecoder