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
Updated the HomeVC, SettingsVC and GlobalSearch UI to use theming
Removed the "fade view" gradients from the various screens
Added a simple log to the PagedDatabaseObserver to make debugging easier
Updated the FullConversationCell to also show the "read" state for messages
Updated the read receipt icons to use SFSymbols directly
Updated the PlaceholderIcon to use the PrimaryColour's as it's colour options
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
Updated to the latest version of GRDB
Renamed some variables for clarity
Updated the "seed viewed" banner on the HomeVC to be driven by a database setting to be consistent with other UI changes
