Fixed a number of scrolling behaviours in the ConversationVC
Fixed a bug with the PagedDataObserver when observing associated data (multiple associations with a single paged result were broken)
Fixed a bug with the PagedDataObserver where it would trigger updates for new entries even if the user is offset from the latest data
Fixed a bug where marking as read wasn't working properly
Fixed a bug where outgoing messages were being considered unread
Added an error state for a failed attachment send
Renamed a few types for clarity
Resolved a bunch of TODOs
Got mentions working again
Got typing indicators working again
Got the notification sound and preview preferences working
Fixed a few issues with attachment image loading
Fixed an issue where enum settings weren't getting stored correctly
Refactored the AppDelegate from Objective C to Swift
Updated the HomeVC to use GRDB
Refactored a number of the Job types to be driven via GRDB and the new JobRunner
Fixed a bug where the LinkPreviewView wouldn't render correctly in dark mode
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)