refactored code, removed *_helper.go files and placed them in *.resolvers.go files for uniformity

backend/graph/steam_helpers.go

@@ -1,22 +0,0 @@
-package graph
-
-import (
-	"fmt"
-
-	"adam-french.co.uk/backend/graph/model"
-	"adam-french.co.uk/backend/services"
-)
-
-func mapSteamGames(games []services.SteamRecentGame) []*model.SteamGame {
-	result := make([]*model.SteamGame, len(games))
-	for i, g := range games {
-		result[i] = &model.SteamGame{
-			AppID:           g.AppID,
-			Name:            g.Name,
-			Playtime2Weeks:  g.Playtime2Weeks,
-			PlaytimeForever: g.PlaytimeForever,
-			HeaderImageURL:  fmt.Sprintf("https://cdn.akamai.steamstatic.com/steam/apps/%d/header.jpg", g.AppID),
-		}
-	}
-	return result
-}