[refactor] 커스텀 예외 적용#54

sehee123 merged 2 commits intodevprgrms-web-devcourse-final-project/WEB5_7_F1_BE:devfrom

refactor/48prgrms-web-devcourse-final-project/WEB5_7_F1_BE:refactor/48Copy head branch name to clipboard