add :: queryAll post api

src/main/kotlin/org/meogo/domain/post/present/dto/response/PostResponse.kt

@@ -0,0 +1,11 @@
+package org.meogo.domain.post.present.dto.response
+
+data class PostResponse(
+    val id: Long,
+    val name: String,
+    val title: String,
+    val content: String,
+    val date: String,
+    val keyWord: List<String>?,
+    val schoolId: Int?
+)

src/main/kotlin/org/meogo/domain/post/service/QueryAllPostService.kt

@@ -0,0 +1,34 @@
+package org.meogo.domain.post.service
+
+import org.meogo.domain.post.domain.PostRepository
+import org.meogo.domain.post.present.dto.response.PostResponse
+import org.springframework.stereotype.Service
+import org.springframework.transaction.annotation.Transactional
+import java.time.LocalDateTime
+import java.time.format.DateTimeFormatter
+
+@Service
+class QueryAllPostService(
+    private val postRepository: PostRepository
+) {
+
+    @Transactional(readOnly = true)
+    fun execute(): List<PostResponse> {
+        val posts = postRepository.findAll()
+
+        return posts.map { post ->
+            PostResponse(
+                id = post.id,
+                name = "익명",
+                title = post.title,
+                content = post.content,
+                date = format(post.date),
+                keyWord = post.keyWord?.split(",")?.map { it.trim() },
+                schoolId = post.schoolId
+            )
+        }.sortedBy { it.id }
+    }
+
+    private fun format(date: LocalDateTime) =
+        date.format(DateTimeFormatter.ofPattern("MM.dd HH:mm"))
+}