RMC Services implementation

[michal-kapala]

There are many RMC requests which don't send proper data yet or are not implemented at all. The services need testing and implementation, which is relatively easy to do.

• [ ] Achievements
• [x] Avatars
• [x] DBG AMM Client Info
• [ ] Find MatchMaking GetParticipantsURLs (16) call
• [ ] Missions
• [x] News
• [ ] Stats
• [x] Weapon Models