Updated the settings screens to have the "rounded group" styling
Added a "loading conversations" label to the Message Requests screen before the conversations load
Removed the legacy UserCell (replaced with the more reusable 'SessionCell')
Renamed a few things to make them more generic and reusable
Removed an unused notification
Refactored the PrivacySettingsViewController
Refactored the ScreenLock code to Swift
Fixed an issue where the match dark/light setting wasn't getting applied on launch
Update the modal styling for the various settings modals
Created the ThemeManager and the system to control the dynamic theming
Started updating the main settings screens
Added the AppearanceViewController and connected it to the ThemeManager
Started adding theme values
Started applying theme values throughout
Cleaned up the creation of the GRDBStorage instance
Fixed an issue where the launch screen wasn't setting it's background colour based on the system setting
Renamed the GRDBStorageError to StorageError (in preparation of legacy 'Storage' relocation)
Consolidated the two Environment classes (in Swift)
Refactored the AppSetup class to Swift
Disabled the attachments and voice message buttons for the first message
Disabled the Disappearing Messages flag for the until the conversation is approved
Fixed a bug where the recipient of a message request could incorrectly get the 'pending approval' state
Refactored some standard auto layout code to use the custom extension code
