Added initial achievement service

src/main/java/ntnu/idatt2016/v233/SmartMat/service/user/AchievementService.java

+package ntnu.idatt2016.v233.SmartMat.service.user;
+
+import lombok.AllArgsConstructor;
+import ntnu.idatt2016.v233.SmartMat.entity.user.Achievement;
+import ntnu.idatt2016.v233.SmartMat.repository.user.AchievementRepository;
+import org.springframework.stereotype.Service;
+
+import java.util.Optional;
+
+/**
+ * Service for achievements
+ *
+ * @author Anders
+ * @version 1.0
+ * @since 19.04.2023
+ */
+
+@Service
+@AllArgsConstructor
+public class AchievementService {
+
+    private AchievementRepository achievementRepository;
+
+    /**
+     * Adds an achievement to the database
+     * @param achievementName name of achievement to add
+     * @param achievementDescription description of achievement to add
+     */
+    public void addAchievement(String achievementName, String achievementDescription){
+        achievementRepository.save(Achievement.builder()
+                .achievementName(achievementName)
+                .achievementDescription(achievementDescription)
+                .build());
+    }
+
+    /**
+     * Gets an achievement from the database
+     * @param achievementName name of achievement to get
+     * @return an optional containing the achievement if it exists
+     */
+    public Optional<Achievement> getAchievement(String achievementName){
+        return achievementRepository.findByAchievementName(achievementName);
+    }
+}