Add AnswerMapper

application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerMapper.java

+package org.fuseri.moduleexercise.answer;
+
+import org.fuseri.model.dto.exercise.AnswerCreateDto;
+import org.fuseri.model.dto.exercise.AnswerDto;
+import org.fuseri.model.dto.exercise.AnswerInQuestionCreateDto;
+import org.fuseri.moduleexercise.common.DomainMapper;
+import org.mapstruct.Mapper;
+
+/**
+ * Mapper between Answers and their corresponding DTOs
+ */
+@Mapper
+public interface AnswerMapper extends DomainMapper<Answer, AnswerDto> {
+
+    /**
+     * Convert DTO of type AnswerCreateDto to Answer
+     *
+     * @param dto DTO to be converted
+     * @return corresponding Answer entity created from DTO
+     */
+    Answer fromCreateDto(AnswerCreateDto dto);
+
+    /**
+     * Convert DTO of type AnswerInQuestionCreateDto to Answer
+     * @param dto DTO to be converted
+     * @return corresponding Answer entity created from DTO
+     */
+    Answer fromCreateDto(AnswerInQuestionCreateDto dto);
+}