SID bitrate in SBA

There are currently defined two SID bitrates in IVAS: 4400 and 5000 bps. However, it seems that some conditions like ivas_total_brate > IVAS_SID_4k4 or ivas_total_brate == IVAS_SID_4k4 are used also at places where the bitrate can actually be 5000.

This concerns e.g. functions ivas_dirac_dec_read_BS(), ivas_qmetadata_to_dirac(), ivas_dec_setup(), updateBuffersForDmxMdctStereo().

A review is needed.