group-by.26.query.sqlpp

Supports flexible degree of parallelism.
Detailed list of changes include:
- Add the IClusterInfoCollector interface and feed that to the compiler;
- Add the number of cores into the heartbeat;
- Add partition calculation in APIFramework;
- Fix partitioning property requirements in binary operators such as Join and UnionAll;
- Fix PushSubplanIntoGroupByRule for type propagation;
- Fix InlineLeftNtsInSubplanJoinFlatteningVisitor for the returned top join operator;
- Add unit test for partition calculation in APIFrameworkTest
- Add integration test SqlppExecutionFullParallelismIT, SqlppExecutionLessParallelismIT,
AqlExecutionFullParallelismIT, and AqlExecutionLessParallelismIT for different
parallelism settings;
- Refactor AQLExecutionTest and SqlppExecutionTest;
- Separate one cluster state test out from AqlExecutionTest.

Change-Id: If70faf52bed995c7098cc343f2fabd1b6c8d96e7
Reviewed-on: https://asterix-gerrit.ics.uci.edu/1398
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
BAD: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Till Westmann <tillw@apache.org>