[#140656091] [Refactor] Heavily refactor vacancy related (efek merge userstory 4 :')

assets/css/custom.css

assets/js/VacancyPage.jsx

assets/js/__test__/components/ApplyModal-test.jsx

assets/js/__test__/components/CancelModal-test.jsx

assets/js/__test__/components/ConfirmationModal-test.jsx

assets/js/__test__/components/Vacancy-test.jsx

assets/js/__test__/components/VacancyList-test.jsx

assets/js/components/ApplyConfirmationModal.jsx

assets/js/components/ApplyModal.jsx

assets/js/components/CancelModal.jsx

assets/js/components/ConfirmationModal.jsx

assets/js/components/ModalAlert.jsx

assets/js/components/Vacancy.jsx

assets/js/components/VacancyList.jsx