[feat] create dto for ranking api

src/main/java/org/pingle/pingleserver/dto/response/RankingIndividualResponse.java

@@ -0,0 +1,6 @@
+package org.pingle.pingleserver.dto.response;
+
+import java.time.LocalDateTime;
+
+public record RankingIndividualResponse (String name, LocalDateTime latestVisitedDate, Long locationCount) {
+}

src/main/java/org/pingle/pingleserver/dto/response/RankingResponse.java

@@ -0,0 +1,17 @@
+package org.pingle.pingleserver.dto.response;
+
+import java.util.List;
+
+public record RankingResponse (int meetingCount, List<RankingIndividualResponse> locations)  {
+    public static RankingResponse of (List<RankingIndividualResponse> responses) {
+        return new RankingResponse(getSumOfMeetings(responses), responses);
+    }
+
+    private static int getSumOfMeetings (List<RankingIndividualResponse> responses) {
+        int sum = 0;
+        for (RankingIndividualResponse response : responses) {
+            sum += response.locationCount();
+        }
+        return sum;
+    }
+}