KORAIL_STORE

[Online Mall] sheet on #32

6. 쇼핑몰 상품 리스트 (online mall product list)
    - response fields change (red text)

[Test Issues]

1.GET /api/mall
  - server error happens
  1) Response 
    a) business_hours (change logic)
      - get from DB (st_mall_hour) with mall_code (sort_no ASC)
      - set text (if multiple, set multiple row with new line)
        "{start_hour} ~ {end_hour}"
    b) station_code / station_name / smart_order_yn : Add (refer to Mall sheet of 20230531 ppt on #32)

2.POST /api/mall_favorites
  - server error happens
  - if user's mall was already registered, return error (status: 400, error_code: "common.error.alreadyRegistered" : "이미 등록되었습니다.")

3.GET /api/mall_product_list
  1) Response 
    a) sold_out_yn / event_yn : Add (refer to Mall sheet of 20230531 ppt on #32)

[API] GET /api/mall_product_list            

1.logic
  1) Response
    a) data > subscribe_yn (NEW)
      if st_product.product_type = 'subscribe', set 'Y'
      else set 'N'