Introduce setting to set lower bound of hash aggregation reduction.

• Default setting of hash group by min reduction % is 0.99. 
• During compilation, we check its effectiveness and adjust it accordingly in SetHashGroupByMinReduction:

  float defaultMinReductionHashAggrFactor = desc.getMinReductionHashAggr();
  float minReductionHashAggrFactor = 1f - ((float) ndvProduct / numRows);
  if (minReductionHashAggrFactor < defaultMinReductionHashAggrFactor) {
        desc.setMinReductionHashAggr(minReductionHashAggrFactor);
  }
  

  For certain queries, this computation turns out to be "0".

This forces operator to skip HashAggregates completely and always ends up choosing streaming mode.