Eng 7326 plannode reorder

This pull requests is basically reordering the Projection node and ORDER BY node for step 1. Step 2 will make the Aggregation node and Projection node inline for certain cases.

For some cases we can not reorder the plan node tree for ORDER BY, I regressed it to use the old plans although they are not efficient.
We weren't doing this before for "columnrefs", only for the other case.
So, this means that we were missing one or both of these effects for some columnrefs? :
    setting of the groupbyCol's alias to the display col's alias
    setting the display col's groupBy to true
    setting the groupbyCol's groupByInDisplay to true