Stereo path encoder functions converted to fixed

[x] Stereo TCX Core Encoder & sub-functions: stereo_tcx_init_enc, InitTnsConfigs, getCoreSamplerateMode2, SetAllowTnsOnWhite, getIgfPresent, sr2fscale, tcxlpc_get_cdk, writeTCXMode, writeTCXWindowing. stereo_tcx_core_enc conversion - partial done.
[x] Functions in ivas_sns_enc.c converted to fixed: sns_1st_cod, sns_2st_cod, sns_avq_cod, sns_avq_cod_stereo
[x] Functions in ivas_stereo_td_analysis.c converted to fixed: Comp_diff_lt_corr, Get_LR_rms, Get_corr_n, Get_dt_lt_ener, limit_idx_Dwnmix, stereo_smooth_LR_transition, stereo_tdm_ener_analysis_SM

EVS 26.444 BE test passes.
decoder pytests:
MLD scores:
Original inputs: 562 failed, 374 skipped
MLD > 10: 46
MLD > 5 : 108
MLD < 5 : 408
+10dB inputs: 562 failed, 374 skipped
MLD > 10: 168
MLD > 5 : 185
MLD < 5 : 209
-10dB inputs: 562 failed, 374 skipped
MLD > 10: 10
MLD > 5 : 50
MLD < 5 : 502

encoder pytests results:
MLD scores:
Original inputs: 562 tests:
MLD > 10: 18
MLD > 5 : 45
MLD < 5 : 499
+10dB inputs: 562 tests:
MLD > 10: 42
MLD > 5 : 128
MLD < 5 : 392
\-10dB inputs: 562 tests:
MLD > 10: 5
MLD > 5 : 19
MLD < 5 : 538