UAR-899 -

Essence:
The ported code from UAR-783 leveraged a different object than that of the old baseline. This resulted in the framework being left without enough information to associate child units with their parent.

Solution:
Change KC 5.2.1 to expose the same objects as KC 3.1.1 in order to gain back sufficient header xml to make these unit hierarchy associations.

Changes:
* src/main/resources/org/kuali/kra/datadictionary/ProposalDevelopmentDocument.xml
    * Changing to use ProposalPersonUnit instead of ProposalPerson, this affects the header xml
* src/main/java/edu/colostate/kc/hierarchyrouting/UnitHierarchyProvider.java
    * Modifying logic to grab unit values from new xml content format
* src/main/java/org/kuali/kra/proposaldevelopment/bo/DevelopmentProposal.java
    * Expose proposalPersonUnit instance variable, so that this data will be available during xml generation