ISM ToDos

Resolve todos:

• ..\lib_com\ivas_error.h(81): IVAS_ERR_INVALID_INDEX, /* ToDo: should be merged with IVAS_ERR_INDEX_OUT_OF_BOUNDS */
• ..\lib_com\ivas_cnst.h(156):#define MAX_BITS_METADATA 2640 /* max. bit-budget of metadata, one channel / / IVAS_fmToDo: to be confirmed for final value once mature
• ..\lib_com\ivas_cnst.h(399): TAG_ISM_LOOP_END = TAG_ISM_LOOP_START + 100, /* IVAS_fmToDo: to be reviewed once the final metadata are defined */

Others:

• #define BRATE_ISM_INACTIVE defined twice
• ivas_ism_metadata_enc() should return error code