Switched the library importing in the launcher to work based on a queue. As a new game is added to the queue, it should find any related data and also add it to the queue. This should result in an easier to maintain importer while reducing the load on the launcher's DAL. This may result in more RAM usage while importing. Local manifests have also been refactored to match manifests in import/export LCX files, removing the old manifest format. This is a large breaking change that will probably break existing game installations. A migration will probably have to be created.
Greatly reduces the amount of memory usage when streaming from the server by:
1. Shedding use of an internal MemoryStream
2. Using HttpCompletionOption.ResponseHeadersRead to start reading the stream without loading all of the HttpContent into memory
SettingsProvider uses IOptionsMonitor to maintain the current value of settings. This gets updates on YML file changes and since it's a single instance (instead of injecting IOptions<Settings>), consumers always have the latest values.
