Whitespace in Primary Key Properties of Populated Template Samples

Work was done in ODS-2008 to force validation on natural key properties, to prevent leading and trailing spaces. There are about ~3k assessment title entries in the sample data which end in an extra space, and are now failing to bulk load in after this change.

Need to update the xml files to remove these trailing spaces.

Also includes fixes to descriptor references on EducationOrganization.xml and StudentDiscipline.xml, to pass bulk loading.