Core coder functions converted to fixed point

[x] Integration of td_stereo_param_updt_fx
[x] Integration of wb_pre_proc, wb_tbe_enc and wb_bwe_enc
[x] integrating and conv stat_noise_uv_enc and update_average_rate function
[x] enc prm rf function
[x] stereo_tcx_core_enc functions
[x] swb_cng_enc function
[x] Converted and integrated msvq_enc
[x] Quantize TCX Spectrum
[x] swb_bwe_enc