Fix #3665 - Refactor timelines reducer (#3686)

* Move ancestors/descendants out of timelines reducer

* Refactor timelines reducer

All types of timelines now have a flat structure and use the same
reducer functions and actions

* Reintroduce some missing behaviours

* Fix wrong import in reports

* Fix includes typo

* Fix issue related to "next" pagination in timelines and notifications

* Fix bug with timeline's initial state, expandNotifications

app/javascript/mastodon/features/public_timeline/index.js

@@ -5,7 +5,8 @@ import StatusListContainer from '../ui/containers/status_list_container';
 import Column from '../../components/column';
 import ColumnHeader from '../../components/column_header';
 import {
-  refreshTimeline,
+  refreshPublicTimeline,
+  expandPublicTimeline,
   updateTimeline,
   deleteFromTimelines,
   connectTimeline,
@@ -61,7 +62,7 @@ class PublicTimeline extends React.PureComponent {
   componentDidMount () {
     const { dispatch, streamingAPIBaseURL, accessToken } = this.props;
 
-    dispatch(refreshTimeline('public'));
+    dispatch(refreshPublicTimeline());
 
     if (typeof this._subscription !== 'undefined') {
       return;
@@ -106,6 +107,10 @@ class PublicTimeline extends React.PureComponent {
     this.column = c;
   }
 
+  handleLoadMore = () => {
+    this.props.dispatch(expandPublicTimeline());
+  }
+
   render () {
     const { intl, columnId, hasUnread, multiColumn } = this.props;
     const pinned = !!columnId;
@@ -126,8 +131,8 @@ class PublicTimeline extends React.PureComponent {
         </ColumnHeader>
 
         <StatusListContainer
-          {...this.props}
-          type='public'
+          timelineId='public'
+          loadMore={this.handleLoadMore}
           trackScroll={!pinned}
           scrollKey={`public_timeline-${columnId}`}
           emptyMessage={<FormattedMessage id='empty_column.public' defaultMessage='There is nothing here! Write something publicly, or manually follow users from other instances to fill it up' />}