Adds the derived table which is created from the queryexpression which was created from a group by with the groupByAlias passed in so we can
find it back if we need to add a field to the derived table.
Namespace:SD.LLBLGen.Pro.LinqSupportClasses Assembly:
SD.LLBLGen.Pro.ORMSupportClasses (in SD.LLBLGen.Pro.ORMSupportClasses.dll) Version: 5.6.0.0 (5.6.19.0117)