`do_search` AssertionError

We have received the following Sentry alert
https://ebm-datalab.sentry.io/issues/5558668558/?alert_rule_id=1877862&alert_type=issue&notification_uuid=088429c9-a418-4ad0-9892-9b56431d5f9d&project=5248013&referrer=slack

def do_search(coding_system, term=None, code=None):
    assert bool(code) != bool(term)
    if term is not None:
        matching_codes = coding_system.search_by_term(term)
    else:
        matching_codes = coding_system.search_by_code(code)

It's not clear what to do as a result of this exception. I think the code and term may be provided by users, in which case we should return a message to them. If not, we should probably raise a more informative error or find a way to stop it from happening.

Start with the do_search function shown in the issue and trace its callers to determine whether code and term can come from users. Review the linked Sentry alert to understand the failing input and decide whether to validate the inputs or raise a more informative error. Done means the reported AssertionError path has a defined, user-appropriate outcome.