1807-authN-smoke-test (#1898)

This PR does the following:

1. Add `login` and `logout` helper functions in `client/__tests__/e2e/cellxgeneActions.js`
2. Add conditional AuthN integration test in `client/__tests__/e2e/e2e.test.js`. The test will only run if env variable `TEST_AUTH_INTEGRATION` is `"true"`, which is only set in `single-cell-infra`'s Github Action flow. Corresponding PR [here](https://github.com/chanzuckerberg/single-cell-infra/pull/198)

client/__tests__/e2e/puppeteer.setup.js

@@ -17,7 +17,9 @@ setDefaultOptions({ timeout: 20 * 1000 });
 
 jest.retryTimes(ENV_DEFAULT.RETRY_ATTEMPTS);
 
-(async () => {
+beforeEach(async () => {
+  await jestPuppeteer.resetBrowser();
+
   const userAgent = await browser.userAgent();
   await page.setUserAgent(`${userAgent}bot`);
 
@@ -53,6 +55,4 @@ jest.retryTimes(ENV_DEFAULT.RETRY_ATTEMPTS);
       }
     }
   });
-})().catch((error) => {
-  console.error("puppeteer.setup.js error", error);
 });