First iteration of usage of GameLevelUpdateDto

...java/com/example/demo/controller/GameLevelController.java

src/main/java/com/example/demo/dto/GameLevelDto.java

src/main/java/com/example/demo/dto/GameLevelUpdateDto.java

src/main/java/com/example/demo/mapper/BeanMapper.java

src/main/java/com/example/demo/service/GameLevelService.java