`INTERVAL '1 hour'` should be equivalent to `INTERVAL 1 HOUR`

**Use case**
People are used to Postgres.
{
    if (isWordCharASCII(*op))
    {
        return ParserKeyword(op).ignore(pos, expected);
    }
    else
    {
        if (strlen(op) == pos->size() && 0 == memcmp(op, pos->begin, pos->size()))
        {
            ++pos;
            return true;
        }
        return false;
    }
}
bool ParserLeftAssociativeBinaryOperatorList::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)