fix: correct data tree child row aggregation in column calcs

[lukecotter]

Summary
This fixes an issue where column calculations for data tree rows could include the parent row repeatedly instead of the child row data.

In the data tree calculation path, [rowsToData] iterates filtered child rows and should push each child row’s data into the calc input. The current logic pushes the parent [row] object instead, which causes incorrect summed values for expanded data tree branches.

• Fixes incorrect totals/sums for data tree child rows
• Affects column calculations when [dataTreeChildColumnCalcs] is enabled and a tree node is expanded

fixes #4705