DRILL-1846: Use max receiver width during stats collection for parallelism planning.  SingleMergeExchange and UnionExchange have a max receive width of 1.  Others can go higher.
DRILL-1788: Test for case-insensitive join. Fix is in Calcite version 0.9-drill-r11.

Bump up optiq version to 0.9-drill-r11.

Refactor TestExampleQueries by moving the Star queries to separate test file.