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)
Fixed an issue where the "block" button would appear in the NoteToSelf swipe menu
Removed the OWSBlockingManager and supporting files
Removed a number of unused classes and methods
Refactored the BlockListUIUtils to Swift