SBA metadata handle

Parts of hMdEnc handle are used only partially in some SBA encoder operating points. E.g. for 3OA at 512 kbps , the consumption is as follows:

ivas_spar_md_enc_o 165 m:sizeof( ivas_spar_md_enc_state_t ) - 34% 1x4189 4189 hMdEnc = (ivas_spar_md_enc_state_t *) count_malloc( sizeof( ivas_spar_md_enc_state_t ) )

Similarly, parts of hMdDec handle are used only partially in some SBA decoder operating points. E.g. for 3OA at 512 kbps and stereo output, the consumption is as follows:

• ivas_spar_md_dec_m 154 m:12 * 4 * sizeof( ivas_band_coeffs_ - 63% 1x2496 2496

hMdDec->spar_md.band_coeffs = (ivas_band_coeffs_t *) count_malloc( IVAS_MAX_NUM_BANDS * MAX_PARAM_SPATIAL_SUBFRAMES * sizeof( ivas_band_coeffs_t ) )

• ivas_spar_md_dec_o 316 m:sizeof( ivas_spar_md_dec_state_t ) - 61% 1x8047 8047

hMdDec = (ivas_spar_md_dec_state_t *) count_malloc( sizeof( ivas_spar_md_dec_state_t ) )

This is a follow-up of #123 (closed) and the issue can be seen when MEM_COUNT_DETAILS is activated.