Feature/rest gamehist service

@Mequrel , @mgruszka , @p4r4noj4 , @Adebski please verify. 
In my personal opinion, we should store players initial positions in map dictionary from https://confluence.iisg.agh.edu.pl/display/ietanks/Front-end 's /api/game/{gameId} POST method, because events store only relative position changes. This should be discussed with fron-end guys @p4r4noj4 , @mgruszka .

public enum EventGroup {
    MISSILES,
    TANKS
}