Added migrations for contacts and started working through thread migration (have contact and closed group threads migrating)
Deprecated usage of ECKeyPair in the migrations (want to be able to remove Curve25519Kit in the future)
Removed the "Back" text from the back buttons
Removed the inset on the 'Path' settings button so the text remains horizontally centered
Hid the settings button from message request threads
Fixed an issue where the back button would remain visible in a conversation when the search field was visible
Fixed an issue where the tintColor of the conversation search field didn't match the global search field
Fixed an issue where sending an attachment response to a message request wouldn't approve the message request
Updated the size and positioning of the message request 'Clear All' button to match the DM 'Next' button
Updated the message request 'Clear All' button to start visible (so it's visible during the push animation) since that's the most likely state it'll be in
Updated the 'Message Requests' cell to use the pinned background colour
Updated the fallback for contact thread names to be a middle-truncated string (4 characters either side)
Got the updated blinding logic working (at least when authenticating a request - still need to deal with message signing and verification)
Storing the server capabilities in the database now so we can correctly blind requests based on them
Renamed the remaining 'v2' functions and classes to just be 'OpenGroup' since there isn't a 'V2' anymore
Cleaned up a few TODOs and functions