Implement adding a user to a list from their profile (#9062)

* Add add user to list from thier profile

* Fix listAdderCss

app/javascript/mastodon/features/ui/components/modal_root.js

@@ -16,6 +16,7 @@ import {
   ReportModal,
   EmbedModal,
   ListEditor,
+  ListAdder,
 } from '../../../features/ui/util/async-components';
 
 const MODAL_COMPONENTS = {
@@ -30,6 +31,7 @@ const MODAL_COMPONENTS = {
   'EMBED': EmbedModal,
   'LIST_EDITOR': ListEditor,
   'FOCAL_POINT': () => Promise.resolve({ default: FocalPointModal }),
+  'LIST_ADDER':ListAdder,
 };
 
 export default class ModalRoot extends React.PureComponent {

app/javascript/mastodon/features/ui/util/async-components.js

@@ -129,3 +129,7 @@ export function EmbedModal () {
 export function ListEditor () {
   return import(/* webpackChunkName: "features/list_editor" */'../../list_editor');
 }
+
+export function ListAdder () {
+  return import(/*webpackChunkName: "features/list_adder" */'../../list_adder');
+}