Utilize Upsert for company data & exchange data submissions

Added the FlexLabs Upsert package to do single-query insert/update operations.
Updated two high-use saving endpoints to utilize upsert in order to avoid the second (or more) query.
Database updates include adding new indexes (in some cases unique indexes) and (for CX data) revising the keys to use the Apex 32-char alphanumeric identifier.