Level differences between MC rendering to stereo and binaural
We noticed internally that the output level for MC can vary between stereo and binaural. E.g.
```
./IVAS_cod -mc 5_1_4 128000 48 scripts/testv/stv514MC48c.wav bit
./IVAS_dec stereo 48 bit out_stereo.wav
./IVAS_dec binaural 48 bit out_binaural.wav
bs1770demo -nchan 2 out_stereo.raw
bs1770demo -nchan 2 out_binaural.raw
```
Gives `Input level: -20.877463` for stereo output and `Input level: -11.101193` for binaural output. The difference is also quite apparent from the waveform/spectrogram:
Stereo output:

Binaural output:

When encoding at 80kbps, the output level is about the same, so this is probably subformat-specific.
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issue