feat(database): add method to find user by email

Author: OtavioXimarelli

src/main/java/com/otavio/aifoodapp/repository/UserRepository.java

@@ -4,10 +4,13 @@
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.security.core.userdetails.UserDetails;
 
+import java.util.Optional;
+
 
 public interface UserRepository extends JpaRepository<User, Long> {
 
 
     UserDetails findByLogin(String login);
 
+    Optional<User> findByEmail(String email);
 }