Add Mods API

[forresthopkinsa]

Should be able to add a new mod, or a mod version (with file)

Acceptance criteria:

• Root of all calls should be /braze/api
• Add new mod: POST /mods
• POST body should include mod's slug, name, author, description, link, and donation link
• Add new mod version: POST /mods/{slug}
• POST body should include name, index (in terms of version sequence; -1 if unspecified), min forge, max forge, and a list of dependencies
• Each version in the dependency list should only include the mod slug and the version name
• Dependency list can be empty
• If slug does not exist, return 404
• Upload file for mod version: POST /mods/{slug}/{version}
• Should be uploading a zip file with the standard Solder structure (will be changed in future)
• If slug or version does not exist, return 404