[feat] cocktail엔티티, 리포지토리, DTO 추가 #9#15

lkw9241 merged 3 commits intodevprgrms-web-devcourse-final-project/WEB6_8_HaeDokCoding_BE:devfrom

feature#9/cocktailDomainprgrms-web-devcourse-final-project/WEB6_8_HaeDokCoding_BE:feature#9/cocktailDomainCopy head branch name to clipboard