[EA3-134] refactor : id명 statId로 변경

Author: endorsement0912

src/main/java/grep/neogulcoder/domain/timevote/entity/TimeVoteStat.java

@@ -20,7 +20,7 @@ public class TimeVoteStat extends BaseEntity {
 
   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
-  private Long id;
+  private Long statId;
 
   @ManyToOne(fetch = FetchType.LAZY)
   @JoinColumn(name = "period_id", nullable = false)