Started subscription overhaul

frontend/src/api.js

frontend/src/components/feedback_list/FeedbackTable.vue

.../src/components/submission_notes/SubmissionCorrection.vue

...ssion_notes/toolbars/AnnotatedSubmissionBottomToolbar.vue

...tend/src/components/subscriptions/SubscriptionForList.vue

frontend/src/components/subscriptions/SubscriptionList.vue

frontend/src/components/subscriptions/SubscriptionType.vue

...nd/src/components/subscriptions/SubscriptionsForStage.vue

frontend/src/pages/PageNotFound.vue

frontend/src/pages/SubscriptionWorkPage.vue

frontend/src/store/actions.js

frontend/src/store/getters.js

frontend/src/store/modules/subscriptions.js

frontend/src/store/mutations.js

frontend/src/store/store.js

frontend/src/util/helpers.js