feat: question dto 에 socket.id 추가

Author: hoeeeeeh

backend/chatServer/src/event/dto/Question.dto.ts

@@ -8,6 +8,7 @@ class QuestionDto {
   msgTime: string = new Date().toISOString();
   msgType: OutgoingMessageType = 'question';
   questionId: number = -1;
+  socketId: string = '';
   questionDone: boolean = false;
 }