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 .

Please do not change the API of the engine module only because it is easier to use it in PlayerEventPojo class in Gameplay module. I would definitely prefer a conversion logic placed in the gameplay module and leave the enum as it was. Now we are leaking REST mapping specifics into the model that should know nothing about this.