Resolve "Make vuex state non-persistent"

frontend/package.json

frontend/src/api.ts

frontend/src/store/modules/authentication.ts

frontend/src/store/plugins/lastInteractionPlugin.ts

frontend/src/store/store.ts

frontend/yarn.lock

functional_tests/test_auto_logout.py

functional_tests/test_feedback_creation.py

functional_tests/util.py