query: support order by on expr alias

[pleiadesian]

When executing TPC-H Q3, a bind error occurs. To fix it, we should support order by on the alias of an expression in select clause.

> SELECT
  L_ORDERKEY,
  SUM(L_EXTENDEDPRICE * (1 - L_DISCOUNT)) AS REVENUE,
  O_ORDERDATE,
  O_SHIPPRIORITY
FROM
  CUSTOMER,
  ORDERS,
  LINEITEM
WHERE
  C_MKTSEGMENT = 'BUILDING'
  AND C_CUSTKEY = O_CUSTKEY
  AND L_ORDERKEY = O_ORDERKEY
  AND O_ORDERDATE < '1995-03-15'
  AND L_SHIPDATE > '1995-03-15'
GROUP BY
  L_ORDERKEY,
  O_ORDERDATE,
  O_SHIPPRIORITY
ORDER BY
  REVENUE DESC,
  O_ORDERDATE,
  L_ORDERKEY
LIMIT 10

bind error: invalid column REVENUE