Merge branch 'json-validation' into HEAD

src/faction/faction.dto.ts

src/faction/faction.service.ts

src/game/game.controller.ts

src/game/game.dto.ts

src/game/game.entity.ts

src/game/game.json-nested.dto.ts

src/game/game.json.dto.ts

src/game/game.service.ts

src/shared/validation.pipe.ts