BASOP and instrumentation changes for stereo decoder and renderer files

EVS 26.444 BE test passes.
pytests results: 595 failed, 381 skipped

MLD scores:
Original inputs:
MLD > 10: 53
MLD > 5 : 123
MLD < 5 : 419

+10dB inputs:
MLD > 10: 184
MLD > 5 : 192
MLD < 5 : 219

-10dB inputs:
MLD > 10: 17
MLD > 5 : 55
MLD < 5 : 523