Removed an unused endpoint
Moved 'Dependencies' into the Utilities folder (also out from being nested within 'OpenGroupAPI' since it can be broader than that)
Finished adding unit tests for the OpenGroupAPI
Updated the OpenGroupManager to be a bit more thread safe
Updated the OpenGroupManager "isModOrAdmin" check to better support the various keys of the current user
Fixed some blinding code to use an existing transaction rather than create it's own ones
Removed the Legacy API calls, handling and types
Refactored the existing unit tests to use Quick
Started adding unit tests for a number of the OpenGroupAPI network models
Added unit tests for the SessionId type
Moved the BlindedIdMapping retrieval logic to ContactUtilities so it's reusable
Added the 'outbox' endpoints (need testing as they aren't deployed to test yet)