Add flow annotations for visualizations and misc

frontend/interfaces/icepick.js

frontend/interfaces/underscore.js

frontend/src/metabase/App.jsx

frontend/src/metabase/auth/auth.js

frontend/src/metabase/debug.js

frontend/src/metabase/icon_paths.js

frontend/src/metabase/lib/api.js

frontend/src/metabase/meta/types/Dataset.js

frontend/src/metabase/reducers.js

frontend/src/metabase/redux/requests.js

frontend/src/metabase/redux/settings.js

frontend/src/metabase/redux/undo.js

frontend/src/metabase/redux/user.js

frontend/src/metabase/routes.jsx

frontend/src/metabase/store.js

frontend/src/metabase/user/actions.js

frontend/src/metabase/visualizations/AreaChart.jsx

frontend/src/metabase/visualizations/BarChart.jsx

frontend/src/metabase/visualizations/Funnel.jsx

frontend/src/metabase/visualizations/LineChart.jsx