Metadata decode changes

[x] Few functions in ivas_qmetadata_com, ivas_qmetadata_dec, ivas_dirac_dec and ivas_spar_decoder converted to fixed.
[x] Few intermediate float functions are present which needs to be cleaned up/updated.
[x] Partial metadata path up.

Pytest results:
For original inputs, +10dB gain and -10dB gain inputs,
573 failed, 1 passed, 381 skipped

MLD deviations:
For original inputs: 1 file with MLD > 5
For +10dB inputs: 7 files with MLD > 5. Debugging in progress.