UI module is type safe

frontend/src/App.vue

frontend/src/components/BaseLayout.vue

frontend/src/components/SubmissionType.vue

.../src/components/submission_notes/base/FeedbackComment.vue

frontend/src/components/subscriptions/SubscriptionList.vue

frontend/src/pages/student/StudentLayout.vue

frontend/src/store/getters.ts

frontend/src/store/modules/ui.ts

frontend/src/store/store.ts

frontend/src/util/helpers.ts

frontend/yarn.lock