Encapsulated methods that are allowed only for admins. Removed ability to add new user, new user must be registered using auth.

src/main/java/com/faf223/expensetrackerfaf/service/UserService.java

@@ -3,7 +3,6 @@ package com.faf223.expensetrackerfaf.service;
 import com.faf223.expensetrackerfaf.model.User;
 import com.faf223.expensetrackerfaf.repository.UserRepository;
 import lombok.RequiredArgsConstructor;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
 import java.util.List;
@@ -14,7 +13,7 @@ public class UserService {
 
     private final UserRepository userRepository;
 
-    public void createOrUpdateUser(User user) {
+    public void updateUser(User user) {
         userRepository.save(user);
     }