[SPARK-13221] [SQL] Fixing GroupingSets when Aggregate Functions Containing GroupBy Columns

Using GroupingSets will generate a wrong result when Aggregate Functions containing GroupBy columns.

This PR is to fix it. Since the code changes are very small. Maybe we also can merge it to 1.6

For example, the following query returns a wrong result:
```scala
sql("select course, sum(earnings) as sum from courseSales group by course, earnings" +
     " grouping sets((), (course), (course, earnings))" +
     " order by course, sum").show()
```
Before the fix, the results are like
```
[null,null]
[Java,null]
[Java,20000.0]
[Java,30000.0]
[dotNET,null]
[dotNET,5000.0]
[dotNET,10000.0]
[dotNET,48000.0]
```
After the fix, the results become correct:
```
[null,113000.0]
[Java,20000.0]
[Java,30000.0]
[Java,50000.0]
[dotNET,5000.0]
[dotNET,10000.0]
[dotNET,48000.0]
[dotNET,63000.0]
```

UPDATE:  This PR also deprecated the external column: GROUPING__ID.

Author: gatorsmile <gatorsmile@gmail.com>

Closes #11100 from gatorsmile/groupingSets.