Harmonize InitTnsConfiguration_ivas_fx() and InitTnsConfiguration_fx()

Bug description

It seems to be possible to harmonize InitTnsConfiguration_ivas_fx() and InitTnsConfiguration_fx().

Ideally,

• InitTnsConfiguration_ivas_fx() should be brought inline with the floating-point code and renamed to InitTnsConfiguration_fx()
• the other function could then probably be removed
• at the same time, also InitTnsConfigs_ivas_fx() and InitTnsConfigs_fx() could be checked, whether they then can be harmonized