Add "Show thread" link to self-replies (#9228)

Fix #4716

app/javascript/mastodon/components/status_list.js

@@ -104,6 +104,7 @@ export default class StatusList extends ImmutablePureComponent {
           onMoveUp={this.handleMoveUp}
           onMoveDown={this.handleMoveDown}
           contextType={timelineId}
+          showThread
         />
       ))
     ) : null;
@@ -117,6 +118,7 @@ export default class StatusList extends ImmutablePureComponent {
           onMoveUp={this.handleMoveUp}
           onMoveDown={this.handleMoveDown}
           contextType={timelineId}
+          showThread
         />
       )).concat(scrollableContent);
     }