Add a minimized view to the new room list

This covers everything except breadcrumbs, as those are somewhat undecided from a design perspective.

src/components/structures/LoggedInView.tsx

@@ -677,7 +677,7 @@ class LoggedInView extends React.PureComponent<IProps, IState> {
         if (SettingsStore.isFeatureEnabled("feature_new_room_list")) {
             // TODO: Supply props like collapsed and disabled to LeftPanel2
             leftPanel = (
-                <LeftPanel2 />
+                <LeftPanel2 isMinimized={this.props.collapseLhs || false} />
             );
         }