Grouping() returns a column is aggregated or not, grouping_id() returns the aggregation levels.

grouping()/grouping_id() could be used with window function, but does not work in having/sort clause, will be fixed by another PR.

The GROUPING__ID/grouping_id() in Hive is wrong (according to docs), we also did it wrongly, this PR change that to match the behavior in most databases (also the docs of Hive).

Author: Davies Liu <davies@databricks.com>

Closes #10677 from davies/grouping.