Stereo path functions conversion/ integration, config and initializations

[x] stereo icbwe enc, tdm_lp_comparison conversion/integration
[x] Conversion of core_signal_analysis_high_bitrate and its subfunctions and integration in ivas_mdct_core_whitening_enc stack
[x] Integration of few functions in pre_proc_front_ivas
[x] Intermediate code cleanup changes
[x] ivas_ism_enc_config stack fixed conversion
[x] tdm downmix function conversion and integration