Condition getUserCondition(final ExpressionOperator expression) {
        return expressionMapper.apply(expression);
    }
IMPORTANT - This must be called after any insert/update to STROOM_USER (and
as part of the same txn) to ensure STROOM_USER_ARCHIVE is up-to-date.
NOT to be called after a delete statement as we want to preserve the details
of deleted users.
stroom-security/stroom-security-impl-db/src/main/java/stroom/security/impl/db/UserDaoImpl.java