Builds a GET_REVOC_REG_DEF request. Request to get a revocation registry definition,
    that Issuer creates for a particular Credential Definition.

    :param submitter_did: (Optional) DID of the read request sender (if not provided then default Libindy DID will be used).
    :param rev_reg_def_id: ID of Revocation Registry Definition in ledger.

    :return: Request result as json.

async def build_get_revoc_reg_def_request(submitter_did: Optional[str],
                                          rev_reg_def_id: str) -> str:
    """
    Builds a GET_REVOC_REG_DEF request. Request to get a revocation registry definition,
    that Issuer creates for a particular Credential Definition.

    :param submitter_did: (Optional) DID of the read request sender (if not provided then default Libindy DID will be used).
    :param rev_reg_def_id: ID of Revocation Registry Definition in ledger.

    :return: Request result as json.
    """

    logger = logging.getLogger(__name__)
    logger.debug("build_get_revoc_reg_def_request: >>> submitter_did: %r, rev_reg_def_id: %r", submitter_did,
                 rev_reg_def_id)

    if not hasattr(build_get_revoc_reg_def_request, "cb"):
        logger.debug("build_get_revoc_reg_def_request: Creating callback")
        build_get_revoc_reg_def_request.cb = create_cb(CFUNCTYPE(None, c_int32, c_int32, c_char_p))

    c_submitter_did = c_char_p(submitter_did.encode('utf-8')) if submitter_did is not None else None
    c_rev_reg_def_id = c_char_p(rev_reg_def_id.encode('utf-8'))

    request_json = await do_call('indy_build_get_revoc_reg_def_request',
                                 c_submitter_did,
                                 c_rev_reg_def_id,
                                 build_get_revoc_reg_def_request.cb)

    res = request_json.decode()
    logger.debug("build_get_revoc_reg_def_request: <<< res: %r", res)
    return res