New API for user ranks

[jimmydorry]

• Allow mods to manually specify ranks (contributor, donor, VIP, etc.) and set whether it will be public or private (for if the mod wants to add logic on how it's announced in-game)
• Allow mods to manually assign people to ranks and set whether it will be public or private (for if the mod wants to add logic on how it's announced in-game)
• Allow admins to manually specify global ranks (Valf, Pro-players) for site reporting and add people to said ranks. Admins will set the rank as public / private (whether it shows up in-mods globally), and the people in said ranks as public / private (whether the public rank of the queried steamID will be shared with the mod)
• Create endpoint that accepts steamIDs and modIDs and returns ranks (if any) for each steamID

NOTE: Ranks done by admins will be either public or private, so admins can choose not to leak sensitive info like who the Valfs and Pro Players are.