Removing idea directory. Fixing bugs

backend/build.gradle

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

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

...nd/src/main/java/hu/ignis/controller/OrderController.java

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

backend/src/main/resources/application.properties

...src/test/java/hu/ignis/controller/AuthControllerTest.java

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

sample_products.sql