broadcastMessage
abstract suspend fun broadcastMessage(message: BroadcastMessage, target: BroadcastMessageTarget): Either<CoreFailure, Unit>
Attempts to send the given BroadcastMessage to suitable recipients.
Will handle all the needed encryption and possible set-up steps
Will not handle connectivity failures and scheduling re-tries in the future. Suitable for fire-and-forget messages that are not belong to any specific Conversation, like changing user availability status.