WIP: Simple cheatdb replacement

[corarona]

• Goal of the PR
  To make cheatdb work again, without anyone having to host anything. (well except github i guess)

• How does the PR work?
  Essentially it makes dragonfire parse a "download_url" field in contentdb JSON which in turn makes it possible to serve it a static json file which contains all the download URLs without the need to replicate contentDB complexities.

• Does it resolve any reported issue?
  Fixes CheatDB is unreachable #48

To do

This PR is a Work in Progress

• Add a "static cheatDB" repository in the dragonfire org (https://github.com/dragonfireclient/static_cheatdb)
  • Add a README to explain the JSON requirements and the intented release workflow (PRs to the static_cheatdb repo)
• Add a JSON with all known clientmods to that repo
• Make the JSON a bit richer e.g. add descriptions
• Figure out if an additional modification makes sense to remove the need to point to /api/packages for the retrieval of the list and make a more suitable URL possible (This probably needs to be done since raw.github does not like the URL parameters dragonfire otherwise adds to the request URL)
• Set default cheatdb URL in dragonfire to that json
• Fix automatic dependency resolving

How to test

• On this branch: verify cheatdb is working again