Updating backend structure

backend/settings.gradle

backend/src/main/java/hu/ignis/BackendApplication.java

backend/src/main/java/hu/ignis/config/RestConfig.java

backend/src/main/java/hu/ignis/config/WebConfig.java

...end/src/main/java/hu/ignis/controller/AuthController.java

backend/src/main/java/hu/ignis/dto/LoginRequest.java

backend/src/main/java/hu/ignis/dto/LoginResponse.java

backend/src/main/java/hu/ignis/model/Order.java

backend/src/main/java/hu/ignis/model/OrderItem.java

backend/src/main/java/hu/ignis/model/Product.java

backend/src/main/java/hu/ignis/model/User.java

...rc/main/java/hu/ignis/repository/OrderItemRepository.java

...nd/src/main/java/hu/ignis/repository/OrderRepository.java

.../src/main/java/hu/ignis/repository/ProductRepository.java

...end/src/main/java/hu/ignis/repository/UserRepository.java

backend/src/test/java/hu/ignis/dto/LoginRequestTest.java

...end/src/test/java/kisbe32/backend/ApiIntegrationTest.java