Review the ways to get row data for Data Table Columns vs View Port Columns.

Context
There is now a clear separation between a Data Table and View Port column data so that

• You can have a hidden column by defining a column on Data Table but not on View Port Column on the View Port Def
• You can have dynamically generated columns on View Port side (e.g. Calculated Column, Mapped Column if Mapped Column Support #1414 gets implemented) which will not exit on the Data Table side

#1368
See linked discussion section
"2) Decouple APIs of DataTable, ViewPort, ViewPortColumns, RowData and Columns (can make you run in circles)"