Gift ID versus other identifiers

For GiveCampus integrations and API.

For the GiveCampus contribution-based Gifts API, the top-level id is the contribution ID. It corresponds to the donation report/deposit report donation_id field backed by that contribution. It is distinct from a processor checkout/charge ID, deposit ID, constituent ID or nested project ID. Reconcile the same report/product scope; event registrations and imported gifts have separate identifiers. A deposit report may have multiple rows for one gift, so matching an ID is not permission to sum every repeated row.