Export write-in designation answers

For GiveCampus reporting.

The standard custom reporting fields include designation_writein and designation_writein2 for the stored write-in answers. Add the relevant supported columns to the deposit/custom report template and export a test gift. A separate custom donor question is not required merely to collect a configured Write-in designation response. Use allocation-level reporting for more complex splits and distinguish the donor’s free text from the fund backend code.