Harmonize generate_comfort_noise_enc_*fx(), configureFdCngEnc_*fx()
# Bug description
The function pairs
* configureFdCngEnc_fx() \<-\> configureFdCngEnc_ivas_fx()
* generate_comfort_noise_enc_fx() \<-\> generate_comfort_noise_enc_ivas_fx()
are almost identical. They could be harmonized with little effort.
issue