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

test/test-utils/client.ts

@@ -80,4 +80,5 @@ export const mockClientMethodsUser = (userId = '@alice:domain') => ({
  */
 export const mockClientMethodsEvents = () => ({
     decryptEventIfNeeded: jest.fn(),
+    getPushActionsForEvent: jest.fn(),
 });