KRACOEUS-7999: Stack trace when trying to view undisclosed Events

More instances where I converted lookups to DataObjectService, for fetching DevelopmentProposal and ProposalPerson objects.
We're getting perilously close to scope creep here. I understand the need to refactor this, but I don't think this JIRA is the place. I can take care of the unused imports and constants, and open a JIRA to refactor this so that we don't return so many users.