Removed a couple remaining TODOs
Added 'standardUserDefaults' to the 'Dependencies' type
Tweaked the OpenGroupAPI to only update the 'lastOpen' timestamp if it successfully polls
Refactored a couple of methods in the ConversationViewItem into swift so we can clean up the OpenGroupAPI more
Updated the OpenGroupAPI so it no longer has static variables for state (shifted to the OpenGroupManager and made them instance variables)
Fixed an encoding issue with the Capabilities.Capability