CRend binaural external renderer function

This is a follow-up of #857 (closed).

The CRend binaural decoding in the external renderer uses the function ivas_rend_crendProcess(). I am wondering whether it is not a leftover and the function ivas_rend_crendProcessSubframe() should be used instead.

This is related to functions renderIsmToBinauralRoom(), renderMcToBinaural(), renderMcToBinauralRoom(), renderMcCustomLsToBinauralRoom(), renderSbaToBinaural(), renderSbaToBinauralRoom().