Test typescriptification - MessagePanel (#8943)

* mv test/components/structures/MessagePanel-test.js test/components/structures/MessagePanel-test.tsx

* convert simpler messagepanel tests to rtl

* add data-testid to eventlistsummary

* convert read marker tests to rtl

* formatting

* remove commented

src/components/views/elements/EventListSummary.tsx

@@ -527,6 +527,7 @@ export default class EventListSummary extends React.Component<IProps> {
         );
 
         return <GenericEventListSummary
+            data-testid={this.props['data-testid']}
             events={this.props.events}
             threshold={this.props.threshold}
             onToggle={this.props.onToggle}