Refactor every interface/endpoint implementation after API bindings are functional

[garhow]

The following must be completed before refactoring:

• Support ISteamRemoteStorage interface #14
• Support ISteamWebAPIUtil interface #13
• Support ISteamUserStats interface #12
• Support ISteamUser interface #11
• Support ISteamNews interface #10
• Support ISteamEconomy interface #9
• Support ISteamApps interface #8
• Support ISiteLicenseService interface #7
• Support IPublishedFileService interface #6
• Support IPlayerService interface #5
• Support IGameServersService interface #4
• Support IEconService interface #3

[marcohoovy]

We should consider having working a builder-patterns solution as a requirement to this as endpoints such as QueryFiles may benefit from such a feature, this would be a breaking change for the consumers