MSAN fixes for stereo, isma, omasa, osba, float cleanup.

[x] MSAN fix for stereo format errors
[x] MSAN fixes for ISM format errors
[x] MSAN fixes for OSBA and OMASA errors
[x] Float code cleanup in lib_rend
[x] MSAN fix for test_sba_enc_system cases

EVS 26.444 BE test passes.
pytests results: 588 failed, 381 skipped

MLD scores:
Original inputs:
MLD > 10: 88\
MLD > 5 : 143
MLD < 5 : 366

+10dB inputs:
MLD > 10: 224
MLD > 5 : 194
MLD < 5 : 179

-10dB inputs:
MLD > 10: 38
MLD > 5 : 89
MLD < 5 : 470