Improve eslint rules (#3147)

* Add semi to ESLint rules

* Add padded-blocks to ESLint rules

* Add comma-dangle to ESLint rules

* add config/webpack and storyboard

* add streaming/

* yarn test:lint -- --fix

app/javascript/mastodon/features/ui/containers/modal_container.js

@@ -4,7 +4,7 @@ import ModalRoot from '../components/modal_root';
 
 const mapStateToProps = state => ({
   type: state.get('modal').modalType,
-  props: state.get('modal').modalProps
+  props: state.get('modal').modalProps,
 });
 
 const mapDispatchToProps = dispatch => ({