Cleaned up the OnionRequestAPI so we don't need the LegacyOnionRequestAPI
Added requests for the user endpoints
Added deprecated flags to the legacy endpoints and functions
Added some logic to start handling the new poll (batch) response
Started adding unit tests for the OpenGroupAPI functions
Added in the v4 onion requests logic
Added in the new pin/unpin APIs
Split up additional legacy methods to try and simplify the refactoring
Added a number of TODOs around usage of legacy request methods
Split the OpenGroupAPIV2 into separate files
Started working on the new auth and blinded-id approaches (new auth working with un-blinded id suggesting blinded-id code is incorrect)
Updated the SOGS request/response types to use Codable
Updated the SOGS Request type to use enums instead of strings for keys (to reduce likelihood of typos breaking things)
Updated SessionMessagingKit to use Codable and JSONEncoder/JSONDecoder instead of the legacy JSONSerialization
Cleaned up some naming conventions in the SessionMessagingKit (calling a URLRequest body 'parameters' is very confusing...)
Removed the custom TSRequest class (just using standard URLRequest everywhere instead)
Added a number of extension functions to enable some more functional-coding styles
Added extensions to Sodium methods to allow scalar multiplication and the ability to hash providing a salt and a personalisation value (both needed for new SOGS auth)
Fixed an issue where the legacy auth for SOGS could crash due to threading issues (multiple threads accessing the same variable)
Fixed an issue where if you were in two rooms in a single SOGS and deleted one of them, the other room would stop getting updates as the server public key was getting removed
