Push projections through Aggregate to CsvTableScan

Create a rule to push the projections used in aggregate functions. From Julian Hyde:

Calcite should realize that Aggregate has an implied Project (because it only uses a few columns) and push that projection into the CsvTableScan, but it doesn’t.

A query scans only the used projection when no aggregation is used:

explain plan for select name from emps;

CsvTableScan(table=[[SALES, EMPS]], fields=[[1]])

But it scans all the projections when an aggregation is used:

explain plan for select max(name) from emps;

EnumerableAggregate(group=[{}], EXPR$0=[MAX($1)])
  CsvTableScan(table=[[SALES, EMPS]], fields=[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]])