Add ability to filter followed accounts' posts by language (#19095)

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

@@ -11,6 +11,7 @@ import VideoModal from './video_modal';
 import BoostModal from './boost_modal';
 import AudioModal from './audio_modal';
 import ConfirmationModal from './confirmation_modal';
+import SubscribedLanguagesModal from 'mastodon/features/subscribed_languages_modal';
 import FocalPointModal from './focal_point_modal';
 import {
   MuteModal,
@@ -39,6 +40,7 @@ const MODAL_COMPONENTS = {
   'LIST_ADDER': ListAdder,
   'COMPARE_HISTORY': CompareHistoryModal,
   'FILTER': FilterModal,
+  'SUBSCRIBED_LANGUAGES': () => Promise.resolve({ default: SubscribedLanguagesModal }),
 };
 
 export default class ModalRoot extends React.PureComponent {