[WIP] Initial Session Pro Integration, Query Refactoring and Bug Fixes

[mpretty-cyro]

• Initial Session Pro backend integration work
• Refactored the OpenGroupManager and OpenGroupManagerCache into a single CommunityManager
  • This now maintains an in-memory cache to make it easier to retrieve the current state without needing to query the database
• Refactored the SessionThreadViewModel and MessageViewModel (see below for more info)
• Refactored OWSAudioPlayer into Swift
• Reworked some config handling logic so all merges happen before processing the merge changes (this way we can handle multi-config changes properly)
• Removed a bunch of GRDB-specific relationship code (just makes things messy since we have raw SQL elsewhere)
• Added some convenience code to clean up the DSL of consuming events
• Updated the code to retrieve group auth via libSession instead of the database
• Updated to the latest libSession
• Updated code to encode and decode messages via libSession (instead of doing directly and just using libSession for crypto)
• Updated code to use strings from libSession instead of hardcoded values
• Fixed a bug where default communities would use auth to retrieve display pics
• Fixed a bug where interactions may not be able to be marked as deleted if there was an attachment without a downloadUrl
• Fixed a few issues with performing UI actions on background threads (mentions "@you badge")
• Fixed a bug where the Toggle ListItemAccessory could swallow touches and make it appear as though something changed when it didn't
• Fixed a bug where the toggle wouldn't be tinted the right colour in SwiftUI screens
• Fixed a bug where determining whether a string was RTL could cause lag
• Fixed a bug where the ObservationBuilder could incorrectly run queries in cancelled contexts resulting in potential buggy outputs
• Fixed a bug where outgoing voice messages might not be able to be played

SessionThreadViewModel Refactor

The SessionThreadViewModel has been renamed to ConversationInfoViewModel and is now a simple struct (as opposed to a FetchableRecord with a handful of behemoth database queries)

The ConversationInfoViewModel and MessageViewModel now get initialised with a ConversationDataCache which is an object that holds a bunch of [ID -> Data] stores for various types that are needed to construct the aforementioned view models. The ConversationDataCache will generally be populated via the ConversationDataHelper which, when combined with our ObservableEvent system, is where the majority of the work for this refactoring has gone. This helper essentially has 4 parts:

• determineFetchRequirements: Reviews any events which have come through and determines whether anything needs to be fetched from the database
• applyNonDatabaseEvents: Updates the cached data directly based on delta information included in the ObservableEvent instances
• fetchFromDatabase: Fetches any data from the database based on the info returned from determineFetchRequirements, this function will also resolve any dependant data that newly fetched objects need if they aren't already in the cache
• fetchFromLibSession: Retrieves requested data from libSession

Using the above setup all screens which contain conversation or message data now use these two view models, and can share the state of the view models between each other to reduce the need to refetch data when entering a new screen

Some additional changes included due to the above are:

• No longer need to pass displayNameRetriever throughout
• Removed deprecated display name retrieval functions
• Removed some duplicate code
• Removed some synchronous database query hacks we needed until refactoring had been completed
• Refactored mentions to be handled by tags
• Refactored and optimised the searching logic (also added some caching)
• Refactored the ThreadSettingsViewModel to use the new ObservationBuilder system
• Refactored the ThreadPickerViewModel to use the new ObservationBuilder system
• Refactored the HomeViewModel to retrieve data using the ConversationDataHelper
• Refactored the ConversationViewModel to retrieve data using the ConversationDataHelper