eQ Payload is missing required field `response_id`

[jcox-dev]

The eQ schema has changed to require a response_id field. The current payload - when launching a survey from Frontstage - is missing that key.

Respondent Home currently implements a function to generate the required response_id, which is defined as:

def build_response_id(case_id, collex_id, iac):
    """
    Builds a response_id from a case ID, a collection exercise ID, and an IAC
    :param case_id: a case UUID
    :param collex_id: a collection exercise UUID
    :param iac: an IAC
    :return: a base-64 encoded sha-256 hash of case_id|collex_id|iac
    """
    hash_string = f'{case_id}|{collex_id}|{iac}'
    m = hashlib.sha256()
    m.update(hash_string.encode('utf-8'))

    logger.debug("Hash created", digest=m.hexdigest(), case_id=case_id, collex_id=collex_id)

    return base64.urlsafe_b64encode(m.digest()).decode()

NB: this implementation imports and makes use of the stdlibs hashlib and base64.