Add announcements (#12662)

* Add announcements

Fix #11006

* Add reactions to announcements

* Add admin UI for announcements

* Add unit tests

* Fix issues

- Add `with_dismissed` param to announcements API
- Fix end date not being formatted when time range is given
- Fix announcement delete causing reactions to send streaming updates
- Fix announcements container growing too wide and mascot too small
- Fix `all_day` being settable when no time range is given
- Change text "Update" to "Announcement"

* Fix scheduler unpublishing announcements before they are due

* Fix filter params not being passed to announcements filter

app/javascript/mastodon/actions/streaming.js

@@ -8,6 +8,7 @@ import {
 } from './timelines';
 import { updateNotifications, expandNotifications } from './notifications';
 import { updateConversations } from './conversations';
+import { fetchAnnouncements, updateAnnouncements, updateReaction as updateAnnouncementsReaction } from './announcements';
 import { fetchFilters } from './filters';
 import { getLocale } from '../locales';
 
@@ -44,6 +45,12 @@ export function connectTimelineStream (timelineId, path, pollingRefresh = null,
         case 'filters_changed':
           dispatch(fetchFilters());
           break;
+        case 'announcement':
+          dispatch(updateAnnouncements(JSON.parse(data.payload)));
+          break;
+        case 'announcement.reaction':
+          dispatch(updateAnnouncementsReaction(JSON.parse(data.payload)));
+          break;
         }
       },
     };
@@ -51,7 +58,9 @@ export function connectTimelineStream (timelineId, path, pollingRefresh = null,
 }
 
 const refreshHomeTimelineAndNotification = (dispatch, done) => {
-  dispatch(expandHomeTimeline({}, () => dispatch(expandNotifications({}, done))));
+  dispatch(expandHomeTimeline({}, () =>
+    dispatch(expandNotifications({}, () =>
+      dispatch(fetchAnnouncements(done))))));
 };
 
 export const connectUserStream      = () => connectTimelineStream('home', 'user', refreshHomeTimelineAndNotification);