[TRACKING] Downloader stability

[imLinguin]

Why

At the moment downloading logic stability is questionable. The downloader is also fairly limited and doesn't support including/excluding files based on their language. We should definitely improve this situation before making any stable releases.

Steps

• Improve stability of the downloader
• Support patching/updating logic
• Support DLC downloads
• Support progressive downloads - be able to play games before they are fully downloaded
  • [DRAFT]: Maxima Server #23 (new arch may be beneficial to support downloading while playing)
• Support selective downloads (game languages, 4k textures etc..)

[wannkunstbeikor]

I think an option to look at the game files like steamdb would also be nice, and then also allowing only specific files to be downloaded