Minor Changes, just added some of the objects which I will implement later

Author: Madhavan7

src/main/java/UserRegistrationUI.java

@@ -0,0 +1,2 @@
+public class UserRegistrationUI {
+}

src/main/java/UserRegistrationUseCase.java

@@ -0,0 +1,2 @@
+public class UserRegistrationUseCase {
+}